From 36ff89bd28d4ad0d1fbbb88488846fa4aa0fcd70 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Tue, 29 Aug 2017 23:45:45 +0200
Subject: [PATCH] style: Remove HasViewportPercentage.

It's not needed since #18268
---
 components/style/custom_properties.rs         |  8 +--
 components/style/macros.rs                    |  7 +--
 components/style/properties/helpers.mako.rs   |  8 +--
 .../helpers/animated_properties.mako.rs       |  1 -
 .../properties/longhand/background.mako.rs    |  1 -
 .../style/properties/longhand/border.mako.rs  |  2 -
 .../style/properties/longhand/box.mako.rs     | 14 +----
 .../style/properties/longhand/color.mako.rs   |  1 -
 .../properties/longhand/counters.mako.rs      |  2 -
 .../style/properties/longhand/font.mako.rs    | 27 +--------
 .../properties/longhand/inherited_box.mako.rs |  2 -
 .../properties/longhand/inherited_svg.mako.rs |  2 -
 .../longhand/inherited_table.mako.rs          |  2 +-
 .../longhand/inherited_text.mako.rs           |  6 --
 .../style/properties/longhand/list.mako.rs    |  3 -
 .../properties/longhand/pointing.mako.rs      |  1 -
 .../properties/longhand/position.mako.rs      |  2 -
 .../style/properties/longhand/table.mako.rs   |  1 -
 .../style/properties/longhand/text.mako.rs    |  2 -
 .../style/properties/longhand/ui.mako.rs      |  1 -
 .../style/properties/properties.mako.rs       | 35 +----------
 components/style/values/computed/angle.rs     |  2 +-
 .../style/values/computed/percentage.rs       |  2 +-
 .../style/values/generics/background.rs       |  2 +-
 .../style/values/generics/basic_shape.rs      |  7 +--
 components/style/values/generics/border.rs    |  8 +--
 components/style/values/generics/counters.rs  |  6 +-
 components/style/values/generics/effects.rs   |  6 +-
 components/style/values/generics/flex.rs      |  2 +-
 components/style/values/generics/gecko.rs     |  2 +-
 components/style/values/generics/grid.rs      |  5 +-
 components/style/values/generics/image.rs     | 30 +++-------
 components/style/values/generics/mod.rs       |  5 +-
 components/style/values/generics/position.rs  |  2 +-
 components/style/values/generics/rect.rs      |  2 +-
 components/style/values/generics/svg.rs       |  8 +--
 components/style/values/generics/text.rs      |  6 +-
 components/style/values/generics/transform.rs | 10 +---
 components/style/values/mod.rs                |  5 +-
 components/style/values/specified/align.rs    |  4 --
 components/style/values/specified/angle.rs    |  2 +-
 components/style/values/specified/border.rs   |  2 +-
 components/style/values/specified/calc.rs     |  9 +--
 components/style/values/specified/color.rs    |  2 -
 components/style/values/specified/effects.rs  |  2 +-
 components/style/values/specified/grid.rs     | 37 +-----------
 components/style/values/specified/image.rs    |  4 +-
 components/style/values/specified/length.rs   | 29 +++------
 components/style/values/specified/mod.rs      |  8 +--
 .../style/values/specified/percentage.rs      |  1 -
 components/style/values/specified/position.rs | 14 +----
 components/style/values/specified/svg.rs      |  1 -
 components/style/values/specified/time.rs     |  4 +-
 .../style/values/specified/transform.rs       |  2 +-
 .../style_derive/has_viewport_percentage.rs   | 42 -------------
 components/style_derive/lib.rs                |  7 ---
 components/style_traits/lib.rs                |  1 -
 components/style_traits/viewport.rs           | 60 -------------------
 tests/unit/style/parsing/value.rs             | 13 +---
 tests/unit/style/properties/mod.rs            |  1 -
 tests/unit/style/properties/viewport.rs       | 27 ---------
 61 files changed, 73 insertions(+), 437 deletions(-)
 delete mode 100644 components/style_derive/has_viewport_percentage.rs
 delete mode 100644 tests/unit/style/properties/viewport.rs

diff --git a/components/style/custom_properties.rs b/components/style/custom_properties.rs
index c4d979f7a7c..f52495120f4 100644
--- a/components/style/custom_properties.rs
+++ b/components/style/custom_properties.rs
@@ -17,7 +17,7 @@ use std::borrow::{Borrow, Cow};
 use std::collections::{HashMap, HashSet};
 use std::fmt;
 use std::hash::Hash;
-use style_traits::{HasViewportPercentage, ToCss, StyleParseError, ParseError};
+use style_traits::{ToCss, StyleParseError, ParseError};
 
 /// A custom property name is just an `Atom`.
 ///
@@ -51,12 +51,6 @@ pub struct SpecifiedValue {
     references: HashSet<Name>,
 }
 
-impl HasViewportPercentage for SpecifiedValue {
-    fn has_viewport_percentage(&self) -> bool {
-        panic!("has_viewport_percentage called before resolving!");
-    }
-}
-
 /// This struct is a cheap borrowed version of a `SpecifiedValue`.
 pub struct BorrowedSpecifiedValue<'a> {
     css: &'a str,
diff --git a/components/style/macros.rs b/components/style/macros.rs
index c766d414001..12be15a182a 100644
--- a/components/style/macros.rs
+++ b/components/style/macros.rs
@@ -57,9 +57,8 @@ macro_rules! define_numbered_css_keyword_enum {
     }
 }
 
-/// A macro for implementing `ComputedValueAsSpecified`, `Parse`
-/// and `HasViewportPercentage` traits for the enums defined
-/// using `define_css_keyword_enum` macro.
+/// A macro for implementing `ComputedValueAsSpecified`, and `Parse` traits for
+/// the enums defined using `define_css_keyword_enum` macro.
 ///
 /// NOTE: We should either move `Parse` trait to `style_traits`
 /// or `define_css_keyword_enum` macro to this crate, but that
@@ -76,7 +75,6 @@ macro_rules! add_impls_for_keyword_enum {
         }
 
         impl $crate::values::computed::ComputedValueAsSpecified for $name {}
-        no_viewport_percentage!($name);
     };
 }
 
@@ -104,6 +102,5 @@ macro_rules! define_keyword_type {
 
         impl $crate::values::computed::ComputedValueAsSpecified for $name {}
         impl $crate::values::animated::AnimatedValueAsComputed for $name {}
-        no_viewport_percentage!($name);
     };
 }
diff --git a/components/style/properties/helpers.mako.rs b/components/style/properties/helpers.mako.rs
index ec22cabd352..76c78e40e24 100644
--- a/components/style/properties/helpers.mako.rs
+++ b/components/style/properties/helpers.mako.rs
@@ -83,8 +83,6 @@
         #[allow(unused_imports)]
         use smallvec::SmallVec;
         use std::fmt;
-        #[allow(unused_imports)]
-        use style_traits::HasViewportPercentage;
         use style_traits::{Separator, ToCss};
 
         pub mod single_value {
@@ -179,7 +177,7 @@
         }
 
         /// The specified value of ${name}.
-        #[derive(Clone, Debug, HasViewportPercentage, PartialEq)]
+        #[derive(Clone, Debug, PartialEq)]
         #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
         pub struct SpecifiedValue(pub Vec<single_value::SpecifiedValue>);
 
@@ -420,7 +418,6 @@
     %>
     <%call expr="longhand(name, keyword=Keyword(name, values, **keyword_kwargs), **kwargs)">
         use properties::longhands::system_font::SystemFont;
-        no_viewport_percentage!(SpecifiedValue);
 
         pub mod computed_value {
             use cssparser::Parser;
@@ -529,7 +526,6 @@
             impl ComputedValueAsSpecified for SpecifiedValue {}
         % endif
 
-        no_viewport_percentage!(SpecifiedValue);
     </%call>
 </%def>
 
@@ -948,7 +944,7 @@
         }
 
         #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-        #[derive(Clone, Debug, HasViewportPercentage, PartialEq, ToCss)]
+        #[derive(Clone, Debug, PartialEq, ToCss)]
         pub struct SpecifiedValue(pub ${length_type});
 
         % if length_type == "MozLength":
diff --git a/components/style/properties/helpers/animated_properties.mako.rs b/components/style/properties/helpers/animated_properties.mako.rs
index 4c2057f61d9..b2299d7f436 100644
--- a/components/style/properties/helpers/animated_properties.mako.rs
+++ b/components/style/properties/helpers/animated_properties.mako.rs
@@ -214,7 +214,6 @@ pub enum TransitionProperty {
     Unsupported(CustomIdent)
 }
 
-no_viewport_percentage!(TransitionProperty);
 
 impl ComputedValueAsSpecified for TransitionProperty {}
 
diff --git a/components/style/properties/longhand/background.mako.rs b/components/style/properties/longhand/background.mako.rs
index f70ef7e06d4..5e608315f19 100644
--- a/components/style/properties/longhand/background.mako.rs
+++ b/components/style/properties/longhand/background.mako.rs
@@ -69,7 +69,6 @@ ${helpers.predefined_type("background-image", "ImageLayer",
         pub struct T(pub RepeatKeyword, pub RepeatKeyword);
     }
 
-    no_viewport_percentage!(SpecifiedValue);
 
     impl ToCss for computed_value::T {
         fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
diff --git a/components/style/properties/longhand/border.mako.rs b/components/style/properties/longhand/border.mako.rs
index f4326fc0399..b6dd5338938 100644
--- a/components/style/properties/longhand/border.mako.rs
+++ b/components/style/properties/longhand/border.mako.rs
@@ -78,7 +78,6 @@ ${helpers.gecko_keyword_conversion(Keyword('border-style',
         use std::fmt;
         use style_traits::ToCss;
         use values::specified::RGBAColor;
-        no_viewport_percentage!(SpecifiedValue);
 
         pub mod computed_value {
             use cssparser::RGBA;
@@ -230,7 +229,6 @@ ${helpers.predefined_type("border-image-outset", "LengthOrNumberRect",
                    spec="https://drafts.csswg.org/css-backgrounds/#border-image-repeat">
     use style_traits::ToCss;
 
-    no_viewport_percentage!(SpecifiedValue);
 
     pub mod computed_value {
         pub use super::RepeatKeyword;
diff --git a/components/style/properties/longhand/box.mako.rs b/components/style/properties/longhand/box.mako.rs
index ae22a94dc4f..b900da81584 100644
--- a/components/style/properties/longhand/box.mako.rs
+++ b/components/style/properties/longhand/box.mako.rs
@@ -36,7 +36,6 @@
     %>
     use values::computed::ComputedValueAsSpecified;
     use style_traits::ToCss;
-    no_viewport_percentage!(SpecifiedValue);
 
     pub mod computed_value {
         pub use super::SpecifiedValue as T;
@@ -222,7 +221,6 @@ ${helpers.single_keyword("position", "static absolute relative fixed",
                                   gecko_pref_ident="float_"
                                   flags="APPLIES_TO_FIRST_LETTER"
                                   spec="https://drafts.csswg.org/css-box/#propdef-float">
-    no_viewport_percentage!(SpecifiedValue);
     impl ToComputedValue for SpecifiedValue {
         type ComputedValue = computed_value::T;
 
@@ -261,7 +259,6 @@ ${helpers.single_keyword("position", "static absolute relative fixed",
                                   gecko_enum_prefix="StyleClear"
                                   gecko_ffi_name="mBreakType"
                                   spec="https://www.w3.org/TR/CSS2/visuren.html#flow-control">
-    no_viewport_percentage!(SpecifiedValue);
     impl ToComputedValue for SpecifiedValue {
         type ComputedValue = computed_value::T;
 
@@ -327,7 +324,7 @@ ${helpers.single_keyword("position", "static absolute relative fixed",
 
     /// The `vertical-align` value.
     #[allow(non_camel_case_types)]
-    #[derive(Clone, Debug, HasViewportPercentage, PartialEq)]
+    #[derive(Clone, Debug, PartialEq)]
     #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
     pub enum SpecifiedValue {
         % for keyword in vertical_align_keywords:
@@ -571,7 +568,6 @@ ${helpers.predefined_type("transition-delay",
             }
         }
     }
-    no_viewport_percentage!(SpecifiedValue);
 
     pub fn parse<'i, 't>(context: &ParserContext, input: &mut Parser<'i, 't>)
                          -> Result<SpecifiedValue,ParseError<'i>> {
@@ -641,7 +637,6 @@ ${helpers.predefined_type("animation-timing-function",
         }
     }
 
-    no_viewport_percentage!(SpecifiedValue);
 
     #[inline]
     pub fn get_initial_value() -> computed_value::T {
@@ -842,7 +837,7 @@ ${helpers.predefined_type(
     /// Multiple transform functions compose a transformation.
     ///
     /// Some transformations can be expressed by other more general functions.
-    #[derive(Clone, Debug, HasViewportPercentage, PartialEq)]
+    #[derive(Clone, Debug, PartialEq)]
     #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
     pub enum SpecifiedOperation {
         /// Represents a 2D 2x3 matrix.
@@ -991,7 +986,7 @@ ${helpers.predefined_type(
         }
     }
 
-    #[derive(Clone, Debug, HasViewportPercentage, PartialEq)]
+    #[derive(Clone, Debug, PartialEq)]
     #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
     pub struct SpecifiedValue(Vec<SpecifiedOperation>);
 
@@ -1705,7 +1700,6 @@ ${helpers.predefined_type("transform-origin",
     use values::computed::ComputedValueAsSpecified;
 
     impl ComputedValueAsSpecified for SpecifiedValue {}
-    no_viewport_percentage!(SpecifiedValue);
 
     pub mod computed_value {
         pub type T = super::SpecifiedValue;
@@ -1850,7 +1844,6 @@ ${helpers.single_keyword("-moz-orient",
     use values::computed::ComputedValueAsSpecified;
 
     impl ComputedValueAsSpecified for SpecifiedValue {}
-    no_viewport_percentage!(SpecifiedValue);
 
     pub mod computed_value {
         pub use super::SpecifiedValue as T;
@@ -1924,7 +1917,6 @@ ${helpers.predefined_type(
     use values::computed::ComputedValueAsSpecified;
 
     impl ComputedValueAsSpecified for SpecifiedValue {}
-    no_viewport_percentage!(SpecifiedValue);
 
     pub mod computed_value {
         pub use super::SpecifiedValue as T;
diff --git a/components/style/properties/longhand/color.mako.rs b/components/style/properties/longhand/color.mako.rs
index 9ee704f1424..a2c2c61a33e 100644
--- a/components/style/properties/longhand/color.mako.rs
+++ b/components/style/properties/longhand/color.mako.rs
@@ -34,7 +34,6 @@
     #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
     #[derive(Clone, Debug, PartialEq, ToCss)]
     pub struct SpecifiedValue(pub Color);
-    no_viewport_percentage!(SpecifiedValue);
 
     pub mod computed_value {
         use cssparser;
diff --git a/components/style/properties/longhand/counters.mako.rs b/components/style/properties/longhand/counters.mako.rs
index 12a4d8d4413..190351895c7 100644
--- a/components/style/properties/longhand/counters.mako.rs
+++ b/components/style/properties/longhand/counters.mako.rs
@@ -23,7 +23,6 @@
     pub use self::computed_value::ContentItem;
 
     impl ComputedValueAsSpecified for SpecifiedValue {}
-    no_viewport_percentage!(SpecifiedValue);
 
     pub mod computed_value {
         use cssparser;
@@ -296,7 +295,6 @@
         computed_value::T(Vec::new())
     }
 
-    no_viewport_percentage!(SpecifiedValue);
 
     impl ToCss for SpecifiedValue {
         fn to_css<W>(&self, dest: &mut W) -> fmt::Result
diff --git a/components/style/properties/longhand/font.mako.rs b/components/style/properties/longhand/font.mako.rs
index 7dc51dca3d4..5d849c746cf 100644
--- a/components/style/properties/longhand/font.mako.rs
+++ b/components/style/properties/longhand/font.mako.rs
@@ -76,7 +76,6 @@ macro_rules! impl_gecko_keyword_conversions {
     use std::fmt;
     use style_traits::ToCss;
 
-    no_viewport_percentage!(SpecifiedValue);
 
     pub mod computed_value {
         use cssparser::{CssStringWriter, Parser, serialize_identifier};
@@ -430,7 +429,6 @@ ${helpers.single_keyword_system("font-variant-caps",
                    spec="https://drafts.csswg.org/css-fonts/#propdef-font-weight">
     use properties::longhands::system_font::SystemFont;
 
-    no_viewport_percentage!(SpecifiedValue);
 
     #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
     #[derive(Clone, Copy, Debug, Eq, PartialEq, ToCss)]
@@ -597,7 +595,7 @@ ${helpers.single_keyword_system("font-variant-caps",
     use app_units::Au;
     use properties::longhands::system_font::SystemFont;
     use std::fmt;
-    use style_traits::{HasViewportPercentage, ToCss};
+    use style_traits::ToCss;
     use values::FONT_MEDIUM_PX;
     use values::computed::NonNegativeAu;
     use values::specified::{AllowQuirks, FontRelativeLength, LengthOrPercentage, NoCalcLength};
@@ -615,15 +613,6 @@ ${helpers.single_keyword_system("font-variant-caps",
         }
     }
 
-    impl HasViewportPercentage for SpecifiedValue {
-        fn has_viewport_percentage(&self) -> bool {
-            match *self {
-                SpecifiedValue::Length(ref lop) => lop.has_viewport_percentage(),
-                _ => false
-            }
-        }
-    }
-
     #[derive(Clone, Debug, PartialEq)]
     #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
     pub enum SpecifiedValue {
@@ -1068,7 +1057,6 @@ ${helpers.single_keyword_system("font-variant-caps",
                    spec="https://drafts.csswg.org/css-fonts/#propdef-font-size-adjust">
     use properties::longhands::system_font::SystemFont;
 
-    no_viewport_percentage!(SpecifiedValue);
 
     #[derive(Clone, Copy, Debug, PartialEq, ToCss)]
     #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
@@ -1190,7 +1178,6 @@ ${helpers.single_keyword_system("font-variant-caps",
     use values::computed::ComputedValueAsSpecified;
 
     impl ComputedValueAsSpecified for SpecifiedValue {}
-    no_viewport_percentage!(SpecifiedValue);
 
     pub mod computed_value {
         pub use super::SpecifiedValue as T;
@@ -1302,7 +1289,6 @@ ${helpers.single_keyword_system("font-kerning",
     use style_traits::ToCss;
     use values::CustomIdent;
 
-    no_viewport_percentage!(SpecifiedValue);
 
     #[derive(Clone, Debug, PartialEq)]
     #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
@@ -1512,7 +1498,6 @@ macro_rules! exclusive_value {
     use std::fmt;
     use style_traits::ToCss;
 
-    no_viewport_percentage!(SpecifiedValue);
 
     bitflags! {
         #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
@@ -1658,7 +1643,6 @@ macro_rules! exclusive_value {
     use std::fmt;
     use style_traits::ToCss;
 
-    no_viewport_percentage!(SpecifiedValue);
 
     bitflags! {
         #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
@@ -1818,7 +1802,6 @@ macro_rules! exclusive_value {
     use std::fmt;
     use style_traits::ToCss;
 
-    no_viewport_percentage!(SpecifiedValue);
 
     bitflags! {
         #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
@@ -1981,7 +1964,6 @@ ${helpers.single_keyword_system("font-variant-position",
         Value(computed_value::T),
         System(SystemFont)
     }
-    no_viewport_percentage!(SpecifiedValue);
 
     <%self:simple_system_boilerplate name="font_feature_settings"></%self:simple_system_boilerplate>
 
@@ -2023,7 +2005,6 @@ https://drafts.csswg.org/css-fonts-4/#low-level-font-variation-settings-control-
 
     pub type SpecifiedValue = computed_value::T;
 
-    no_viewport_percentage!(SpecifiedValue);
 
 
     pub mod computed_value {
@@ -2051,7 +2032,6 @@ https://drafts.csswg.org/css-fonts-4/#low-level-font-variation-settings-control-
     use std::fmt;
     use style_traits::ToCss;
     use byteorder::{BigEndian, ByteOrder};
-    no_viewport_percentage!(SpecifiedValue);
 
     #[derive(Clone, Debug, Eq, PartialEq)]
     #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
@@ -2209,7 +2189,6 @@ https://drafts.csswg.org/css-fonts-4/#low-level-font-variation-settings-control-
     pub use self::computed_value::T as SpecifiedValue;
 
     impl ComputedValueAsSpecified for SpecifiedValue {}
-    no_viewport_percentage!(SpecifiedValue);
 
     pub mod computed_value {
         use Atom;
@@ -2269,7 +2248,6 @@ https://drafts.csswg.org/css-fonts-4/#low-level-font-variation-settings-control-
     use std::fmt;
     use style_traits::ToCss;
 
-    no_viewport_percentage!(SpecifiedValue);
 
     pub mod computed_value {
         pub type T = i8;
@@ -2369,7 +2347,7 @@ ${helpers.single_keyword("-moz-math-variant",
     use gecko_bindings::structs::NS_MATHML_DEFAULT_SCRIPT_MIN_SIZE_PT;
     use values::specified::length::{AU_PER_PT, FontBaseSize, NoCalcLength};
 
-    #[derive(Clone, Debug, HasViewportPercentage, PartialEq, ToCss)]
+    #[derive(Clone, Debug, PartialEq, ToCss)]
     pub struct SpecifiedValue(pub NoCalcLength);
 
     pub mod computed_value {
@@ -2418,7 +2396,6 @@ ${helpers.single_keyword("-moz-math-variant",
     pub use self::computed_value::T as SpecifiedValue;
 
     impl ComputedValueAsSpecified for SpecifiedValue {}
-    no_viewport_percentage!(SpecifiedValue);
 
     pub mod computed_value {
         use std::fmt;
diff --git a/components/style/properties/longhand/inherited_box.mako.rs b/components/style/properties/longhand/inherited_box.mako.rs
index 32c9c4440ce..16779dfbf03 100644
--- a/components/style/properties/longhand/inherited_box.mako.rs
+++ b/components/style/properties/longhand/inherited_box.mako.rs
@@ -66,7 +66,6 @@ ${helpers.single_keyword("image-rendering",
     use style_traits::ToCss;
     use values::specified::Angle;
 
-    no_viewport_percentage!(SpecifiedValue);
 
     use std::f64::consts::PI;
     const TWO_PI: f64 = 2.0 * PI;
@@ -259,7 +258,6 @@ ${helpers.single_keyword("image-rendering",
     use style_traits::ToCss;
     use values::computed::ComputedValueAsSpecified;
 
-    no_viewport_percentage!(SpecifiedValue);
 
     #[derive(Clone, Copy, Debug, Eq, PartialEq)]
     #[cfg_attr(feature = "servo", derive(HeapSizeOf, Deserialize, Serialize))]
diff --git a/components/style/properties/longhand/inherited_svg.mako.rs b/components/style/properties/longhand/inherited_svg.mako.rs
index 36ad2598a7b..9b05707f33c 100644
--- a/components/style/properties/longhand/inherited_svg.mako.rs
+++ b/components/style/properties/longhand/inherited_svg.mako.rs
@@ -259,7 +259,6 @@ ${helpers.predefined_type("marker-end", "UrlOrNone", "Either::Second(None_)",
         }
     }
 
-    no_viewport_percentage!(SpecifiedValue);
 
     impl ComputedValueAsSpecified for SpecifiedValue { }
 </%helpers:longhand>
@@ -271,7 +270,6 @@ ${helpers.predefined_type("marker-end", "UrlOrNone", "Either::Second(None_)",
     use values::CustomIdent;
     use values::computed::ComputedValueAsSpecified;
 
-    no_viewport_percentage!(SpecifiedValue);
 
     impl ComputedValueAsSpecified for SpecifiedValue { }
 
diff --git a/components/style/properties/longhand/inherited_table.mako.rs b/components/style/properties/longhand/inherited_table.mako.rs
index b98cab4204a..c7e060124bf 100644
--- a/components/style/properties/longhand/inherited_table.mako.rs
+++ b/components/style/properties/longhand/inherited_table.mako.rs
@@ -60,7 +60,7 @@ ${helpers.single_keyword("caption-side", "top bottom",
     }
 
     #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-    #[derive(Clone, Debug, HasViewportPercentage, PartialEq, ToCss)]
+    #[derive(Clone, Debug, PartialEq, ToCss)]
     pub struct SpecifiedValue {
         pub horizontal: NonNegativeLength,
         pub vertical: Option<NonNegativeLength>,
diff --git a/components/style/properties/longhand/inherited_text.mako.rs b/components/style/properties/longhand/inherited_text.mako.rs
index 0e74957c499..346d864b3bb 100644
--- a/components/style/properties/longhand/inherited_text.mako.rs
+++ b/components/style/properties/longhand/inherited_text.mako.rs
@@ -70,7 +70,6 @@ ${helpers.single_keyword("word-break",
                                   animation_value_type="discrete"
                                   flags="APPLIES_TO_PLACEHOLDER",
                                   spec="https://drafts.csswg.org/css-text/#propdef-text-justify">
-    no_viewport_percentage!(SpecifiedValue);
 
     impl ToComputedValue for SpecifiedValue {
         type ComputedValue = computed_value::T;
@@ -114,7 +113,6 @@ ${helpers.single_keyword("text-align-last",
 <%helpers:longhand name="text-align" animation_value_type="discrete"
                    flags="APPLIES_TO_PLACEHOLDER"
                    spec="https://drafts.csswg.org/css-text/#propdef-text-align">
-    no_viewport_percentage!(SpecifiedValue);
     pub mod computed_value {
         use style_traits::ToCss;
         macro_rules! define_text_align {
@@ -292,7 +290,6 @@ ${helpers.predefined_type("word-spacing",
     use values::computed::ComputedValueAsSpecified;
 
     impl ComputedValueAsSpecified for SpecifiedValue {}
-    no_viewport_percentage!(SpecifiedValue);
 
     #[derive(Clone, Copy, Debug, PartialEq)]
     #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
@@ -379,7 +376,6 @@ ${helpers.predefined_type("word-spacing",
                                   spec="https://drafts.csswg.org/css-text/#propdef-white-space">
     use values::computed::ComputedValueAsSpecified;
     impl ComputedValueAsSpecified for SpecifiedValue {}
-    no_viewport_percentage!(SpecifiedValue);
 
     % if product != "gecko":
     impl SpecifiedValue {
@@ -435,7 +431,6 @@ ${helpers.predefined_type(
     use style_traits::ToCss;
     use unicode_segmentation::UnicodeSegmentation;
 
-    no_viewport_percentage!(SpecifiedValue);
 
     pub mod computed_value {
         #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
@@ -638,7 +633,6 @@ ${helpers.predefined_type(
     }
 
     impl ComputedValueAsSpecified for SpecifiedValue {}
-    no_viewport_percentage!(SpecifiedValue);
 
     pub fn get_initial_value() -> computed_value::T {
         SpecifiedValue(HorizontalWritingModeValue::Over, VerticalWritingModeValue::Right)
diff --git a/components/style/properties/longhand/list.mako.rs b/components/style/properties/longhand/list.mako.rs
index f18d92ebb13..2540922ca2e 100644
--- a/components/style/properties/longhand/list.mako.rs
+++ b/components/style/properties/longhand/list.mako.rs
@@ -50,7 +50,6 @@ ${helpers.single_keyword("list-style-position", "outside inside", animation_valu
         }
 
         impl ComputedValueAsSpecified for SpecifiedValue {}
-        no_viewport_percentage!(SpecifiedValue);
 
         #[cfg(feature = "gecko")]
         impl SpecifiedValue {
@@ -116,7 +115,6 @@ ${helpers.single_keyword("list-style-position", "outside inside", animation_valu
 
 
     impl ComputedValueAsSpecified for SpecifiedValue {}
-    no_viewport_percentage!(SpecifiedValue);
 
     #[inline]
     pub fn get_initial_value() -> computed_value::T {
@@ -157,7 +155,6 @@ ${helpers.single_keyword("list-style-position", "outside inside", animation_valu
     }
 
     impl ComputedValueAsSpecified for SpecifiedValue {}
-    no_viewport_percentage!(SpecifiedValue);
 
     impl ToCss for SpecifiedValue {
         fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
diff --git a/components/style/properties/longhand/pointing.mako.rs b/components/style/properties/longhand/pointing.mako.rs
index dd8f40fd76f..121e5193b4c 100644
--- a/components/style/properties/longhand/pointing.mako.rs
+++ b/components/style/properties/longhand/pointing.mako.rs
@@ -14,7 +14,6 @@
     use values::specified::url::SpecifiedUrl;
 
     impl ComputedValueAsSpecified for SpecifiedValue {}
-    no_viewport_percentage!(SpecifiedValue);
 
     pub mod computed_value {
         #[cfg(feature = "gecko")]
diff --git a/components/style/properties/longhand/position.mako.rs b/components/style/properties/longhand/position.mako.rs
index 68f3c0b2719..03c5d155588 100644
--- a/components/style/properties/longhand/position.mako.rs
+++ b/components/style/properties/longhand/position.mako.rs
@@ -311,7 +311,6 @@ ${helpers.predefined_type("object-position",
         }
     }
 
-    no_viewport_percentage!(SpecifiedValue);
     impl ComputedValueAsSpecified for SpecifiedValue {}
 
     impl ToCss for computed_value::T {
@@ -454,7 +453,6 @@ ${helpers.predefined_type("object-position",
         pub columns: Range<u32>,
     }
 
-    no_viewport_percentage!(TemplateAreas);
     impl ComputedValueAsSpecified for TemplateAreas {}
 
     impl Parse for TemplateAreas {
diff --git a/components/style/properties/longhand/table.mako.rs b/components/style/properties/longhand/table.mako.rs
index 48984916fd6..68f40e22d37 100644
--- a/components/style/properties/longhand/table.mako.rs
+++ b/components/style/properties/longhand/table.mako.rs
@@ -17,7 +17,6 @@ ${helpers.single_keyword("table-layout", "auto fixed",
     use values::computed::ComputedValueAsSpecified;
 
     impl ComputedValueAsSpecified for SpecifiedValue {}
-    no_viewport_percentage!(SpecifiedValue);
     pub type SpecifiedValue = computed_value::T;
     pub mod computed_value {
         use std::fmt;
diff --git a/components/style/properties/longhand/text.mako.rs b/components/style/properties/longhand/text.mako.rs
index 2f39d38302c..0bb640e02e2 100644
--- a/components/style/properties/longhand/text.mako.rs
+++ b/components/style/properties/longhand/text.mako.rs
@@ -18,7 +18,6 @@
     use std::fmt;
     use style_traits::ToCss;
 
-    no_viewport_percentage!(SpecifiedValue);
 
     #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
     #[derive(Clone, Debug, Eq, PartialEq, ToCss)]
@@ -150,7 +149,6 @@ ${helpers.single_keyword("unicode-bidi",
     use values::computed::ComputedValueAsSpecified;
 
     impl ComputedValueAsSpecified for SpecifiedValue {}
-    no_viewport_percentage!(SpecifiedValue);
 
     bitflags! {
         #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
diff --git a/components/style/properties/longhand/ui.mako.rs b/components/style/properties/longhand/ui.mako.rs
index 1663c379e3c..c33f41a654e 100644
--- a/components/style/properties/longhand/ui.mako.rs
+++ b/components/style/properties/longhand/ui.mako.rs
@@ -51,7 +51,6 @@ ${helpers.single_keyword("-moz-window-shadow", "none default menu tooltip sheet"
     use style_traits::ToCss;
     use values::computed::ComputedValueAsSpecified;
 
-    no_viewport_percentage!(SpecifiedValue);
 
     pub mod computed_value {
         #[derive(Clone, Copy, Debug, PartialEq)]
diff --git a/components/style/properties/properties.mako.rs b/components/style/properties/properties.mako.rs
index c351ac218eb..a45c9937821 100644
--- a/components/style/properties/properties.mako.rs
+++ b/components/style/properties/properties.mako.rs
@@ -36,7 +36,7 @@ use selector_parser::PseudoElement;
 use selectors::parser::SelectorParseError;
 #[cfg(feature = "servo")] use servo_config::prefs::PREFS;
 use shared_lock::StylesheetGuards;
-use style_traits::{PARSING_MODE_DEFAULT, HasViewportPercentage, ToCss, ParseError};
+use style_traits::{PARSING_MODE_DEFAULT, ToCss, ParseError};
 use style_traits::{PropertyDeclarationParseError, StyleParseError, ValueParseError};
 use stylesheets::{CssRuleType, MallocSizeOf, MallocSizeOfFn, Origin, UrlExtraData};
 #[cfg(feature = "servo")] use values::Either;
@@ -873,19 +873,6 @@ impl UnparsedValue {
     }
 }
 
-impl<'a, T: HasViewportPercentage> HasViewportPercentage for DeclaredValue<'a, T> {
-    fn has_viewport_percentage(&self) -> bool {
-        match *self {
-            DeclaredValue::Value(ref v) => v.has_viewport_percentage(),
-            DeclaredValue::WithVariables(_) => {
-                panic!("DeclaredValue::has_viewport_percentage without \
-                        resolving variables!")
-            },
-            DeclaredValue::CSSWideKeyword(_) => false,
-        }
-    }
-}
-
 impl<'a, T: ToCss> ToCss for DeclaredValue<'a, T> {
     fn to_css<W>(&self, dest: &mut W) -> fmt::Result
         where W: fmt::Write,
@@ -1299,26 +1286,6 @@ pub enum PropertyDeclaration {
     Custom(::custom_properties::Name, DeclaredValueOwned<Box<::custom_properties::SpecifiedValue>>),
 }
 
-impl HasViewportPercentage for PropertyDeclaration {
-    fn has_viewport_percentage(&self) -> bool {
-        match *self {
-            % for property in data.longhands:
-                PropertyDeclaration::${property.camel_case}(ref val) => {
-                    val.has_viewport_percentage()
-                },
-            % endfor
-            PropertyDeclaration::WithVariables(..) => {
-                panic!("DeclaredValue::has_viewport_percentage without \
-                        resolving variables!")
-            },
-            PropertyDeclaration::CSSWideKeyword(..) => false,
-            PropertyDeclaration::Custom(_, ref val) => {
-                val.borrow().has_viewport_percentage()
-            }
-        }
-    }
-}
-
 impl fmt::Debug for PropertyDeclaration {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         self.id().to_css(f)?;
diff --git a/components/style/values/computed/angle.rs b/components/style/values/computed/angle.rs
index 467a9501196..9dd159354ff 100644
--- a/components/style/values/computed/angle.rs
+++ b/components/style/values/computed/angle.rs
@@ -14,7 +14,7 @@ use values::distance::{ComputeSquaredDistance, SquaredDistance};
 /// A computed angle.
 #[animate(fallback = "Self::animate_fallback")]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf, Deserialize, Serialize))]
-#[derive(Animate, Clone, Copy, Debug, HasViewportPercentage, PartialEq)]
+#[derive(Animate, Clone, Copy, Debug, PartialEq)]
 #[derive(PartialOrd, ToAnimatedZero)]
 pub enum Angle {
     /// An angle with degree unit.
diff --git a/components/style/values/computed/percentage.rs b/components/style/values/computed/percentage.rs
index 533bd751616..994d4fbbff9 100644
--- a/components/style/values/computed/percentage.rs
+++ b/components/style/values/computed/percentage.rs
@@ -11,7 +11,7 @@ use values::{CSSFloat, serialize_percentage};
 /// A computed percentage.
 #[cfg_attr(feature = "servo", derive(Deserialize, HeapSizeOf, Serialize))]
 #[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, Default)]
-#[derive(HasViewportPercentage, PartialEq, PartialOrd, ToAnimatedZero)]
+#[derive(PartialEq, PartialOrd, ToAnimatedZero)]
 pub struct Percentage(pub CSSFloat);
 
 impl Percentage {
diff --git a/components/style/values/generics/background.rs b/components/style/values/generics/background.rs
index abcfb655eec..f9050469c74 100644
--- a/components/style/values/generics/background.rs
+++ b/components/style/values/generics/background.rs
@@ -7,7 +7,7 @@
 /// A generic value for the `background-size` property.
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
 #[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug)]
-#[derive(HasViewportPercentage, PartialEq, ToComputedValue, ToCss)]
+#[derive(PartialEq, ToComputedValue, ToCss)]
 pub enum BackgroundSize<LengthOrPercentageOrAuto> {
     /// `<width> <height>`
     Explicit {
diff --git a/components/style/values/generics/basic_shape.rs b/components/style/values/generics/basic_shape.rs
index 019ed6599e2..1e892a781a4 100644
--- a/components/style/values/generics/basic_shape.rs
+++ b/components/style/values/generics/basic_shape.rs
@@ -6,7 +6,7 @@
 //! types that are generic over their `ToCss` implementations.
 
 use std::fmt;
-use style_traits::{HasViewportPercentage, ToCss};
+use style_traits::ToCss;
 use values::animated::{Animate, Procedure, ToAnimatedZero};
 use values::computed::ComputedValueAsSpecified;
 use values::distance::{ComputeSquaredDistance, SquaredDistance};
@@ -159,11 +159,6 @@ impl<B, T, U> ToAnimatedZero for ShapeSource<B, T, U> {
     }
 }
 
-impl<B, T, U> HasViewportPercentage for ShapeSource<B, T, U> {
-    #[inline]
-    fn has_viewport_percentage(&self) -> bool { false }
-}
-
 impl<L> ToCss for InsetRect<L>
     where L: ToCss + PartialEq
 {
diff --git a/components/style/values/generics/border.rs b/components/style/values/generics/border.rs
index 052ef579099..53d813f459b 100644
--- a/components/style/values/generics/border.rs
+++ b/components/style/values/generics/border.rs
@@ -11,7 +11,7 @@ use values::generics::rect::Rect;
 
 /// A generic value for a single side of a `border-image-width` property.
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Clone, Copy, Debug, HasViewportPercentage, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, PartialEq, ToComputedValue, ToCss)]
 pub enum BorderImageSideWidth<LengthOrPercentage, Number> {
     /// `<length-or-percentage>`
     Length(LengthOrPercentage),
@@ -22,7 +22,7 @@ pub enum BorderImageSideWidth<LengthOrPercentage, Number> {
 }
 
 /// A generic value for the `border-image-slice` property.
-#[derive(Clone, Copy, Debug, HasViewportPercentage, PartialEq, ToComputedValue)]
+#[derive(Clone, Copy, Debug, PartialEq, ToComputedValue)]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
 pub struct BorderImageSlice<NumberOrPercentage> {
     /// The offsets.
@@ -35,7 +35,7 @@ pub struct BorderImageSlice<NumberOrPercentage> {
 ///
 /// https://drafts.csswg.org/css-backgrounds-3/#border-radius
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, HasViewportPercentage)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug)]
 #[derive(PartialEq, ToComputedValue)]
 pub struct BorderRadius<LengthOrPercentage> {
     /// The top left radius.
@@ -50,7 +50,7 @@ pub struct BorderRadius<LengthOrPercentage> {
 
 /// A generic value for `border-*-radius` longhand properties.
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, HasViewportPercentage)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug)]
 #[derive(PartialEq, ToComputedValue)]
 pub struct BorderCornerRadius<L>(pub Size2D<L>);
 
diff --git a/components/style/values/generics/counters.rs b/components/style/values/generics/counters.rs
index 180359af764..c6ea4425a39 100644
--- a/components/style/values/generics/counters.rs
+++ b/components/style/values/generics/counters.rs
@@ -5,7 +5,7 @@
 //! Generic types for counters-related CSS values.
 
 use std::fmt;
-use style_traits::{HasViewportPercentage, ToCss};
+use style_traits::ToCss;
 use values::CustomIdent;
 
 /// A generic value for the `counter-increment` property.
@@ -22,10 +22,6 @@ impl<I> CounterIncrement<I> {
     }
 }
 
-impl<I> HasViewportPercentage for CounterIncrement<I> {
-    #[inline] fn has_viewport_percentage(&self) -> bool { false }
-}
-
 impl<I> ToCss for CounterIncrement<I>
 where
     I: ToCss,
diff --git a/components/style/values/generics/effects.rs b/components/style/values/generics/effects.rs
index 5d95ae19a8f..b0f061e874e 100644
--- a/components/style/values/generics/effects.rs
+++ b/components/style/values/generics/effects.rs
@@ -11,7 +11,7 @@ use values::specified::url::SpecifiedUrl;
 
 /// A generic value for a single `box-shadow`.
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Animate, Clone, Debug, HasViewportPercentage, PartialEq)]
+#[derive(Animate, Clone, Debug, PartialEq)]
 #[derive(ToAnimatedValue, ToAnimatedZero)]
 pub struct BoxShadow<Color, SizeLength, BlurShapeLength, ShapeLength> {
     /// The base shadow.
@@ -25,7 +25,7 @@ pub struct BoxShadow<Color, SizeLength, BlurShapeLength, ShapeLength> {
 
 /// A generic value for a single `filter`.
 #[cfg_attr(feature = "servo", derive(Deserialize, HeapSizeOf, Serialize))]
-#[derive(Clone, Debug, HasViewportPercentage, PartialEq, ToAnimatedValue, ToComputedValue, ToCss)]
+#[derive(Clone, Debug, PartialEq, ToAnimatedValue, ToComputedValue, ToCss)]
 pub enum Filter<Angle, Factor, Length, DropShadow> {
     /// `blur(<length>)`
     #[css(function)]
@@ -67,7 +67,7 @@ pub enum Filter<Angle, Factor, Length, DropShadow> {
 /// Contrary to the canonical order from the spec, the color is serialised
 /// first, like in Gecko and Webkit.
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Animate, Clone, ComputeSquaredDistance, Debug, HasViewportPercentage)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Debug)]
 #[derive(PartialEq, ToAnimatedValue, ToAnimatedZero, ToCss)]
 pub struct SimpleShadow<Color, SizeLength, ShapeLength> {
     /// Color.
diff --git a/components/style/values/generics/flex.rs b/components/style/values/generics/flex.rs
index 3d7f2098fce..0ee864555de 100644
--- a/components/style/values/generics/flex.rs
+++ b/components/style/values/generics/flex.rs
@@ -8,7 +8,7 @@ use values::computed::Percentage;
 
 /// A generic value for the `flex-basis` property.
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Clone, Copy, Debug, HasViewportPercentage, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, PartialEq, ToComputedValue, ToCss)]
 pub enum FlexBasis<LengthOrPercentage> {
     /// `auto`
     Auto,
diff --git a/components/style/values/generics/gecko.rs b/components/style/values/generics/gecko.rs
index 31c62078861..d450b138e38 100644
--- a/components/style/values/generics/gecko.rs
+++ b/components/style/values/generics/gecko.rs
@@ -6,7 +6,7 @@
 //! unshipped at some point in the future.
 
 /// A generic value for scroll snap points.
-#[derive(Clone, Copy, Debug, HasViewportPercentage, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, PartialEq, ToComputedValue, ToCss)]
 pub enum ScrollSnapPoint<LengthOrPercentage> {
     /// `none`
     None,
diff --git a/components/style/values/generics/grid.rs b/components/style/values/generics/grid.rs
index 4786174825d..95b7a50c728 100644
--- a/components/style/values/generics/grid.rs
+++ b/components/style/values/generics/grid.rs
@@ -130,7 +130,6 @@ impl Parse for GridLine {
 }
 
 impl ComputedValueAsSpecified for GridLine {}
-no_viewport_percentage!(GridLine);
 
 define_css_keyword_enum!{ TrackKeyword:
     "auto" => Auto,
@@ -182,7 +181,7 @@ impl<L: ToCss> ToCss for TrackBreadth<L> {
 ///
 /// https://drafts.csswg.org/css-grid/#typedef-track-size
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Clone, Debug, HasViewportPercentage, PartialEq)]
+#[derive(Clone, Debug, PartialEq)]
 pub enum TrackSize<L> {
     /// A flexible `<track-breadth>`
     Breadth(TrackBreadth<L>),
@@ -372,7 +371,6 @@ impl Parse for RepeatCount {
 }
 
 impl ComputedValueAsSpecified for RepeatCount {}
-no_viewport_percentage!(RepeatCount);
 
 /// The structure containing `<line-names>` and `<track-size>` values.
 ///
@@ -666,7 +664,6 @@ impl ToCss for LineNameList {
 }
 
 impl ComputedValueAsSpecified for LineNameList {}
-no_viewport_percentage!(LineNameList);
 
 /// Variants for `<grid-template-rows> | <grid-template-columns>`
 /// Subgrid deferred to Level 2 spec due to lack of implementation.
diff --git a/components/style/values/generics/image.rs b/components/style/values/generics/image.rs
index 3e977759d70..b9c5a036697 100644
--- a/components/style/values/generics/image.rs
+++ b/components/style/values/generics/image.rs
@@ -10,7 +10,7 @@ use Atom;
 use cssparser::serialize_identifier;
 use custom_properties::SpecifiedValue;
 use std::fmt;
-use style_traits::{HasViewportPercentage, ToCss};
+use style_traits::ToCss;
 use values::computed::ComputedValueAsSpecified;
 
 /// An [image].
@@ -36,7 +36,7 @@ pub enum Image<Gradient, MozImageRect, ImageUrl> {
 /// A CSS gradient.
 /// https://drafts.csswg.org/css-images/#gradients
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Clone, Debug, HasViewportPercentage, PartialEq, ToComputedValue)]
+#[derive(Clone, Debug, PartialEq, ToComputedValue)]
 pub struct Gradient<LineDirection, Length, LengthOrPercentage, Position, Color, Angle> {
     /// Gradients can be linear or radial.
     pub kind: GradientKind<LineDirection, Length, LengthOrPercentage, Position, Angle>,
@@ -50,7 +50,7 @@ pub struct Gradient<LineDirection, Length, LengthOrPercentage, Position, Color,
     pub compat_mode: CompatMode,
 }
 
-#[derive(Clone, Copy, Debug, HasViewportPercentage, PartialEq, ToComputedValue)]
+#[derive(Clone, Copy, Debug, PartialEq, ToComputedValue)]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
 /// Whether we used the modern notation or the compatibility `-webkit`, `-moz` prefixes.
 pub enum CompatMode {
@@ -64,7 +64,7 @@ pub enum CompatMode {
 
 /// A gradient kind.
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Clone, Copy, Debug, HasViewportPercentage, PartialEq, ToComputedValue)]
+#[derive(Clone, Copy, Debug, PartialEq, ToComputedValue)]
 pub enum GradientKind<LineDirection, Length, LengthOrPercentage, Position, Angle> {
     /// A linear gradient.
     Linear(LineDirection),
@@ -73,7 +73,7 @@ pub enum GradientKind<LineDirection, Length, LengthOrPercentage, Position, Angle
 }
 
 /// A radial gradient's ending shape.
-#[derive(Clone, Copy, Debug, HasViewportPercentage, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, PartialEq, ToComputedValue, ToCss)]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
 pub enum EndingShape<Length, LengthOrPercentage> {
     /// A circular gradient.
@@ -83,7 +83,7 @@ pub enum EndingShape<Length, LengthOrPercentage> {
 }
 
 /// A circle shape.
-#[derive(Clone, Copy, Debug, HasViewportPercentage, PartialEq, ToComputedValue)]
+#[derive(Clone, Copy, Debug, PartialEq, ToComputedValue)]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
 pub enum Circle<Length> {
     /// A circle radius.
@@ -93,7 +93,7 @@ pub enum Circle<Length> {
 }
 
 /// An ellipse shape.
-#[derive(Clone, Copy, Debug, HasViewportPercentage, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, PartialEq, ToComputedValue, ToCss)]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
 pub enum Ellipse<LengthOrPercentage> {
     /// An ellipse pair of radii.
@@ -111,13 +111,12 @@ define_css_keyword_enum!(ShapeExtent:
     "contain" => Contain,
     "cover" => Cover
 );
-no_viewport_percentage!(ShapeExtent);
 impl ComputedValueAsSpecified for ShapeExtent {}
 
 /// A gradient item.
 /// https://drafts.csswg.org/css-images-4/#color-stop-syntax
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Clone, Copy, Debug, HasViewportPercentage, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, PartialEq, ToComputedValue, ToCss)]
 pub enum GradientItem<Color, LengthOrPercentage> {
     /// A color stop.
     ColorStop(ColorStop<Color, LengthOrPercentage>),
@@ -127,7 +126,7 @@ pub enum GradientItem<Color, LengthOrPercentage> {
 
 /// A color stop.
 /// https://drafts.csswg.org/css-images/#typedef-color-stop-list
-#[derive(Clone, Copy, HasViewportPercentage, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, PartialEq, ToComputedValue, ToCss)]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
 pub struct ColorStop<Color, LengthOrPercentage> {
     /// The color of this stop.
@@ -215,17 +214,6 @@ impl<G, R, U> ToCss for Image<G, R, U>
     }
 }
 
-impl<G, R, U> HasViewportPercentage for Image<G, R, U>
-    where G: HasViewportPercentage
-{
-    fn has_viewport_percentage(&self) -> bool {
-        match *self {
-            Image::Gradient(ref gradient) => gradient.has_viewport_percentage(),
-            _ => false,
-        }
-    }
-}
-
 impl<D, L, LoP, P, C, A> ToCss for Gradient<D, L, LoP, P, C, A>
     where D: LineDirection, L: ToCss, LoP: ToCss, P: ToCss, C: ToCss, A: ToCss
 {
diff --git a/components/style/values/generics/mod.rs b/components/style/values/generics/mod.rs
index 0638743da61..bd2695813c1 100644
--- a/components/style/values/generics/mod.rs
+++ b/components/style/values/generics/mod.rs
@@ -92,7 +92,6 @@ impl CounterStyleOrNone {
     }
 }
 
-no_viewport_percentage!(CounterStyleOrNone);
 
 impl Parse for CounterStyleOrNone {
     fn parse<'i, 't>(context: &ParserContext, input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i>> {
@@ -268,12 +267,12 @@ impl ToCss for FontSettingTagFloat {
 
 /// A wrapper of Non-negative values.
 #[cfg_attr(feature = "servo", derive(Deserialize, HeapSizeOf, Serialize))]
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, HasViewportPercentage)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug)]
 #[derive(PartialEq, PartialOrd, ToAnimatedZero, ToComputedValue, ToCss)]
 pub struct NonNegative<T>(pub T);
 
 /// A wrapper of greater-than-or-equal-to-one values.
 #[cfg_attr(feature = "servo", derive(Deserialize, HeapSizeOf, Serialize))]
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, HasViewportPercentage)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug)]
 #[derive(PartialEq, PartialOrd, ToAnimatedZero, ToComputedValue, ToCss)]
 pub struct GreaterThanOrEqualToOne<T>(pub T);
diff --git a/components/style/values/generics/position.rs b/components/style/values/generics/position.rs
index 5a014ca62fd..5c1b2333559 100644
--- a/components/style/values/generics/position.rs
+++ b/components/style/values/generics/position.rs
@@ -8,7 +8,7 @@
 /// A generic type for representing a CSS [position](https://drafts.csswg.org/css-values/#position).
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
 #[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug)]
-#[derive(HasViewportPercentage, PartialEq, ToAnimatedZero, ToComputedValue)]
+#[derive(PartialEq, ToAnimatedZero, ToComputedValue)]
 pub struct Position<H, V> {
     /// The horizontal component of position.
     pub horizontal: H,
diff --git a/components/style/values/generics/rect.rs b/components/style/values/generics/rect.rs
index 7c5a7fabfb3..3b98fc664ec 100644
--- a/components/style/values/generics/rect.rs
+++ b/components/style/values/generics/rect.rs
@@ -13,7 +13,7 @@ use style_traits::{ToCss, ParseError};
 /// serialize as few components as possible, like for example in `border-width`.
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
 #[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug)]
-#[derive(HasViewportPercentage, PartialEq, ToComputedValue)]
+#[derive(PartialEq, ToComputedValue)]
 pub struct Rect<T>(pub T, pub T, pub T, pub T);
 
 impl<T> Rect<T> {
diff --git a/components/style/values/generics/svg.rs b/components/style/values/generics/svg.rs
index 87b0a74bc23..9b0f19ae4bc 100644
--- a/components/style/values/generics/svg.rs
+++ b/components/style/values/generics/svg.rs
@@ -104,7 +104,7 @@ impl<ColorType: Parse, UrlPaintServer: Parse> Parse for SVGPaint<ColorType, UrlP
 /// A value of <length> | <percentage> | <number> for svg which allow unitless length.
 /// https://www.w3.org/TR/SVG11/painting.html#StrokeProperties
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Clone, Copy, Debug, HasViewportPercentage, PartialEq, ToAnimatedValue)]
+#[derive(Clone, Copy, Debug, PartialEq, ToAnimatedValue)]
 #[derive(ToAnimatedZero, ToComputedValue, ToCss)]
 pub enum SvgLengthOrPercentageOrNumber<LengthOrPercentage, Number> {
     /// <length> | <percentage>
@@ -187,7 +187,7 @@ impl <LengthOrPercentageType: Parse, NumberType: Parse> Parse for
 /// An SVG length value supports `context-value` in addition to length.
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
 #[derive(Clone, ComputeSquaredDistance, Copy, Debug, PartialEq)]
-#[derive(HasViewportPercentage, ToAnimatedValue, ToAnimatedZero)]
+#[derive(ToAnimatedValue, ToAnimatedZero)]
 #[derive(ToComputedValue, ToCss)]
 pub enum SVGLength<LengthType> {
     /// `<length> | <percentage> | <number>`
@@ -198,7 +198,7 @@ pub enum SVGLength<LengthType> {
 
 /// Generic value for stroke-dasharray.
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Clone, ComputeSquaredDistance, Debug, HasViewportPercentage, PartialEq, ToAnimatedValue, ToComputedValue)]
+#[derive(Clone, ComputeSquaredDistance, Debug, PartialEq, ToAnimatedValue, ToComputedValue)]
 pub enum SVGStrokeDashArray<LengthType> {
     /// `[ <length> | <percentage> | <number> ]#`
     Values(Vec<LengthType>),
@@ -232,7 +232,7 @@ impl<LengthType> ToCss for SVGStrokeDashArray<LengthType> where LengthType: ToCs
 /// An SVG opacity value accepts `context-{fill,stroke}-opacity` in
 /// addition to opacity value.
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Clone, ComputeSquaredDistance, Copy, Debug, HasViewportPercentage)]
+#[derive(Clone, ComputeSquaredDistance, Copy, Debug)]
 #[derive(PartialEq, ToAnimatedZero, ToComputedValue, ToCss)]
 pub enum SVGOpacity<OpacityType> {
     /// `<opacity-value>`
diff --git a/components/style/values/generics/text.rs b/components/style/values/generics/text.rs
index c1d55bd541e..ca14885d6c0 100644
--- a/components/style/values/generics/text.rs
+++ b/components/style/values/generics/text.rs
@@ -13,7 +13,7 @@ use values::distance::{ComputeSquaredDistance, SquaredDistance};
 
 /// A generic value for the `initial-letter` property.
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Clone, Copy, Debug, HasViewportPercentage, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, PartialEq, ToComputedValue, ToCss)]
 pub enum InitialLetter<Number, Integer> {
     /// `normal`
     Normal,
@@ -31,7 +31,7 @@ impl<N, I> InitialLetter<N, I> {
 
 /// A generic spacing value for the `letter-spacing` and `word-spacing` properties.
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Clone, Copy, Debug, HasViewportPercentage, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, PartialEq, ToComputedValue, ToCss)]
 pub enum Spacing<Value> {
     /// `normal`
     Normal,
@@ -111,7 +111,7 @@ where
 /// A generic value for the `line-height` property.
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
 #[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug)]
-#[derive(HasViewportPercentage, PartialEq, ToAnimatedValue, ToCss)]
+#[derive(PartialEq, ToAnimatedValue, ToCss)]
 pub enum LineHeight<Number, LengthOrPercentage> {
     /// `normal`
     Normal,
diff --git a/components/style/values/generics/transform.rs b/components/style/values/generics/transform.rs
index 82e18f436ff..bcd57510e1a 100644
--- a/components/style/values/generics/transform.rs
+++ b/components/style/values/generics/transform.rs
@@ -5,13 +5,13 @@
 //! Generic types for CSS values that are related to transformations.
 
 use std::fmt;
-use style_traits::{HasViewportPercentage, ToCss};
+use style_traits::ToCss;
 use values::CSSFloat;
 
 /// A generic 2D transformation matrix.
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Clone, Copy, Debug, HasViewportPercentage, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, PartialEq, ToComputedValue, ToCss)]
 #[css(comma, function)]
 pub struct Matrix<T, U = T> {
     pub a: T,
@@ -24,7 +24,7 @@ pub struct Matrix<T, U = T> {
 
 /// A generic transform origin.
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, HasViewportPercentage)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug)]
 #[derive(PartialEq, ToAnimatedZero, ToComputedValue, ToCss)]
 pub struct TransformOrigin<H, V, Depth> {
     /// The horizontal origin.
@@ -78,10 +78,6 @@ impl<H, V, D> TransformOrigin<H, V, D> {
     }
 }
 
-impl<I, N> HasViewportPercentage for TimingFunction<I, N> {
-    fn has_viewport_percentage(&self) -> bool { false }
-}
-
 impl<Integer, Number> TimingFunction<Integer, Number> {
     /// `ease`
     #[inline]
diff --git a/components/style/values/mod.rs b/components/style/values/mod.rs
index 6c54e434808..076e52de6af 100644
--- a/components/style/values/mod.rs
+++ b/components/style/values/mod.rs
@@ -54,7 +54,7 @@ pub fn serialize_dimension<W>(value: CSSFloat, unit: &str, dest: &mut W)
 
 /// Convenience void type to disable some properties and values through types.
 #[cfg_attr(feature = "servo", derive(Deserialize, HeapSizeOf, Serialize))]
-#[derive(Clone, Copy, Debug, HasViewportPercentage, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, PartialEq, ToComputedValue, ToCss)]
 pub enum Impossible {}
 
 impl Parse for Impossible {
@@ -68,7 +68,7 @@ impl Parse for Impossible {
 
 /// A struct representing one of two kinds of values.
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, HasViewportPercentage)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy)]
 #[derive(PartialEq, ToAnimatedValue, ToAnimatedZero, ToComputedValue, ToCss)]
 pub enum Either<A, B> {
     /// The first value.
@@ -196,4 +196,3 @@ define_css_keyword_enum!(ExtremumLength:
                          "-moz-min-content" => MinContent,
                          "-moz-fit-content" => FitContent,
                          "-moz-available" => FillAvailable);
-no_viewport_percentage!(ExtremumLength);
diff --git a/components/style/values/specified/align.rs b/components/style/values/specified/align.rs
index 2b1b52fa1bc..c5b6212e89c 100644
--- a/components/style/values/specified/align.rs
+++ b/components/style/values/specified/align.rs
@@ -173,7 +173,6 @@ impl ToCss for AlignJustifyContent {
     }
 }
 
-no_viewport_percentage!(AlignJustifyContent);
 
 impl Parse for AlignJustifyContent {
     // normal | <baseline-position> |
@@ -223,7 +222,6 @@ impl AlignJustifySelf {
     }
 }
 
-no_viewport_percentage!(AlignJustifySelf);
 
 impl Parse for AlignJustifySelf {
     // auto | normal | stretch | <baseline-position> |
@@ -261,7 +259,6 @@ impl AlignItems {
     }
 }
 
-no_viewport_percentage!(AlignItems);
 
 impl Parse for AlignItems {
     // normal | stretch | <baseline-position> |
@@ -305,7 +302,6 @@ impl JustifyItems {
     }
 }
 
-no_viewport_percentage!(JustifyItems);
 
 impl Parse for JustifyItems {
     // auto | normal | stretch | <baseline-position> |
diff --git a/components/style/values/specified/angle.rs b/components/style/values/specified/angle.rs
index bb926318b01..3990d6b3b0a 100644
--- a/components/style/values/specified/angle.rs
+++ b/components/style/values/specified/angle.rs
@@ -20,7 +20,7 @@ use values::specified::calc::CalcNode;
 /// value serialization. Therefore we are storing a computed angle inside
 /// to hold the actual value and its unit.
 #[cfg_attr(feature = "servo", derive(HeapSizeOf, Deserialize, Serialize))]
-#[derive(Clone, Copy, Debug, HasViewportPercentage, PartialEq)]
+#[derive(Clone, Copy, Debug, PartialEq)]
 pub struct Angle {
     value: ComputedAngle,
     was_calc: bool,
diff --git a/components/style/values/specified/border.rs b/components/style/values/specified/border.rs
index 419074babe6..19863b5d1de 100644
--- a/components/style/values/specified/border.rs
+++ b/components/style/values/specified/border.rs
@@ -18,7 +18,7 @@ use values::specified::length::{Length, LengthOrPercentage};
 
 /// A specified value for a single side of the `border-width` property.
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Clone, Debug, HasViewportPercentage, PartialEq, ToCss)]
+#[derive(Clone, Debug, PartialEq, ToCss)]
 pub enum BorderSideWidth {
     /// `thin`
     Thin,
diff --git a/components/style/values/specified/calc.rs b/components/style/values/specified/calc.rs
index 7f82c047578..93db7730f37 100644
--- a/components/style/values/specified/calc.rs
+++ b/components/style/values/specified/calc.rs
@@ -11,7 +11,7 @@ use cssparser::{Parser, Token, BasicParseError};
 use parser::ParserContext;
 use std::ascii::AsciiExt;
 use std::fmt;
-use style_traits::{HasViewportPercentage, ToCss, ParseError, StyleParseError};
+use style_traits::{ToCss, ParseError, StyleParseError};
 use style_traits::values::specified::AllowedLengthType;
 use values::{CSSInteger, CSSFloat};
 use values::computed;
@@ -82,13 +82,6 @@ pub struct CalcLengthOrPercentage {
     pub mozmm: Option<CSSFloat>,
 }
 
-impl HasViewportPercentage for CalcLengthOrPercentage {
-    fn has_viewport_percentage(&self) -> bool {
-        self.vw.is_some() || self.vh.is_some() ||
-        self.vmin.is_some() || self.vmax.is_some()
-    }
-}
-
 impl ToCss for CalcLengthOrPercentage {
     /// https://drafts.csswg.org/css-values/#calc-serialize
     ///
diff --git a/components/style/values/specified/color.rs b/components/style/values/specified/color.rs
index 9040fc06a62..724f8eea54b 100644
--- a/components/style/values/specified/color.rs
+++ b/components/style/values/specified/color.rs
@@ -44,7 +44,6 @@ pub enum Color {
     InheritFromBodyQuirk,
 }
 
-no_viewport_percentage!(Color);
 
 #[cfg(feature = "gecko")]
 mod gecko {
@@ -305,7 +304,6 @@ impl ToComputedValue for Color {
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
 pub struct RGBAColor(pub Color);
 
-no_viewport_percentage!(RGBAColor);
 
 impl Parse for RGBAColor {
     fn parse<'i, 't>(context: &ParserContext, input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i>> {
diff --git a/components/style/values/specified/effects.rs b/components/style/values/specified/effects.rs
index 977067be582..cd248224623 100644
--- a/components/style/values/specified/effects.rs
+++ b/components/style/values/specified/effects.rs
@@ -35,7 +35,7 @@ pub type Filter = GenericFilter<Angle, Factor, NonNegativeLength, SimpleShadow>;
 pub type Filter = GenericFilter<Angle, Factor, NonNegativeLength, Impossible>;
 
 /// A value for the `<factor>` parts in `Filter`.
-#[derive(Clone, Debug, HasViewportPercentage, PartialEq, ToCss)]
+#[derive(Clone, Debug, PartialEq, ToCss)]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
 pub struct Factor(NumberOrPercentage);
 
diff --git a/components/style/values/specified/grid.rs b/components/style/values/specified/grid.rs
index 72ce404d25c..13268392c04 100644
--- a/components/style/values/specified/grid.rs
+++ b/components/style/values/specified/grid.rs
@@ -9,7 +9,7 @@ use cssparser::{Parser, Token, BasicParseError};
 use parser::{Parse, ParserContext};
 use std::ascii::AsciiExt;
 use std::mem;
-use style_traits::{HasViewportPercentage, ParseError, StyleParseError};
+use style_traits::{ParseError, StyleParseError};
 use values::{CSSFloat, CustomIdent};
 use values::generics::grid::{GridTemplateComponent, RepeatCount, TrackBreadth, TrackKeyword, TrackRepeat};
 use values::generics::grid::{LineNameList, TrackSize, TrackList, TrackListType};
@@ -38,17 +38,6 @@ impl Parse for TrackBreadth<LengthOrPercentage> {
     }
 }
 
-impl HasViewportPercentage for TrackBreadth<LengthOrPercentage> {
-    #[inline]
-    fn has_viewport_percentage(&self) -> bool {
-        if let TrackBreadth::Breadth(ref lop) = *self {
-            lop.has_viewport_percentage()
-        } else {
-            false
-        }
-    }
-}
-
 impl Parse for TrackSize<LengthOrPercentage> {
     fn parse<'i, 't>(context: &ParserContext, input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i>> {
         if let Ok(b) = input.try(|i| TrackBreadth::parse(context, i)) {
@@ -175,13 +164,6 @@ impl TrackRepeat<LengthOrPercentage> {
     }
 }
 
-impl HasViewportPercentage for TrackRepeat<LengthOrPercentage> {
-    #[inline]
-    fn has_viewport_percentage(&self) -> bool {
-        self.track_sizes.iter().any(|ref v| v.has_viewport_percentage())
-    }
-}
-
 impl Parse for TrackList<LengthOrPercentage> {
     fn parse<'i, 't>(context: &ParserContext, input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i>> {
         // Merge the line names while parsing values. The resulting values will
@@ -278,13 +260,6 @@ impl Parse for TrackList<LengthOrPercentage> {
     }
 }
 
-impl HasViewportPercentage for TrackList<LengthOrPercentage> {
-    #[inline]
-    fn has_viewport_percentage(&self) -> bool {
-        self.values.iter().any(|ref v| v.has_viewport_percentage())
-    }
-}
-
 impl Parse for GridTemplateComponent<LengthOrPercentage> {
     // FIXME: Derive Parse (probably with None_)
     fn parse<'i, 't>(context: &ParserContext, input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i>> {
@@ -307,13 +282,3 @@ impl GridTemplateComponent<LengthOrPercentage> {
         LineNameList::parse(context, input).map(GridTemplateComponent::Subgrid)
     }
 }
-
-impl HasViewportPercentage for GridTemplateComponent<LengthOrPercentage> {
-    #[inline]
-    fn has_viewport_percentage(&self) -> bool {
-        match *self {
-            GridTemplateComponent::TrackList(ref l) => l.has_viewport_percentage(),
-            _ => false,
-        }
-    }
-}
diff --git a/components/style/values/specified/image.rs b/components/style/values/specified/image.rs
index 42f44043328..7caf67cf472 100644
--- a/components/style/values/specified/image.rs
+++ b/components/style/values/specified/image.rs
@@ -85,7 +85,7 @@ pub type GradientKind = GenericGradientKind<
 >;
 
 /// A specified gradient line direction.
-#[derive(Clone, Debug, HasViewportPercentage, PartialEq)]
+#[derive(Clone, Debug, PartialEq)]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
 pub enum LineDirection {
     /// An angular direction.
@@ -105,7 +105,7 @@ pub enum LineDirection {
 }
 
 /// A binary enum to hold either Position or LegacyPosition.
-#[derive(Clone, Debug, HasViewportPercentage, PartialEq, ToCss)]
+#[derive(Clone, Debug, PartialEq, ToCss)]
 #[cfg(feature = "gecko")]
 pub enum GradientPosition {
     /// 1, 2, 3, 4-valued <position>.
diff --git a/components/style/values/specified/length.rs b/components/style/values/specified/length.rs
index 20951d9dcbc..490161a4df1 100644
--- a/components/style/values/specified/length.rs
+++ b/components/style/values/specified/length.rs
@@ -14,7 +14,7 @@ use parser::{Parse, ParserContext};
 use std::{cmp, fmt, mem};
 use std::ascii::AsciiExt;
 use std::ops::Mul;
-use style_traits::{HasViewportPercentage, ToCss, ParseError, StyleParseError};
+use style_traits::{ToCss, ParseError, StyleParseError};
 use style_traits::values::specified::AllowedLengthType;
 use stylesheets::CssRuleType;
 use super::{AllowQuirks, Number, ToComputedValue, Percentage};
@@ -183,12 +183,6 @@ pub enum ViewportPercentageLength {
     Vmax(CSSFloat)
 }
 
-impl HasViewportPercentage for ViewportPercentageLength {
-    fn has_viewport_percentage(&self) -> bool {
-        true
-    }
-}
-
 impl ToCss for ViewportPercentageLength {
     fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
         match *self {
@@ -422,15 +416,6 @@ pub enum NoCalcLength {
     Physical(PhysicalLength),
 }
 
-impl HasViewportPercentage for NoCalcLength {
-    fn has_viewport_percentage(&self) -> bool {
-        match *self {
-            NoCalcLength::ViewportPercentage(_) => true,
-            _ => false,
-        }
-    }
-}
-
 impl ToCss for NoCalcLength {
     fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
         match *self {
@@ -545,7 +530,7 @@ impl NoCalcLength {
 ///
 /// https://drafts.csswg.org/css-values/#lengths
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Clone, Debug, HasViewportPercentage, PartialEq, ToCss)]
+#[derive(Clone, Debug, PartialEq, ToCss)]
 pub enum Length {
     /// The internal length type that cannot parse `calc`
     NoCalc(NoCalcLength),
@@ -759,7 +744,7 @@ pub type NonNegativeLengthOrNumber = Either<NonNegativeLength, NonNegativeNumber
 /// A length or a percentage value.
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Clone, Debug, HasViewportPercentage, PartialEq, ToCss)]
+#[derive(Clone, Debug, PartialEq, ToCss)]
 pub enum LengthOrPercentage {
     Length(NoCalcLength),
     Percentage(computed::Percentage),
@@ -929,7 +914,7 @@ impl LengthOrPercentage {
 /// Either a `<length>`, a `<percentage>`, or the `auto` keyword.
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Clone, Debug, HasViewportPercentage, PartialEq, ToCss)]
+#[derive(Clone, Debug, PartialEq, ToCss)]
 pub enum LengthOrPercentageOrAuto {
     Length(NoCalcLength),
     Percentage(computed::Percentage),
@@ -1045,7 +1030,7 @@ impl LengthOrPercentageOrAuto {
 
 /// Either a `<length>`, a `<percentage>`, or the `none` keyword.
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Clone, Debug, HasViewportPercentage, PartialEq, ToCss)]
+#[derive(Clone, Debug, PartialEq, ToCss)]
 #[allow(missing_docs)]
 pub enum LengthOrPercentageOrNone {
     Length(NoCalcLength),
@@ -1193,7 +1178,7 @@ impl LengthOrNumber {
 /// `auto`, and cannot be `none`.
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Clone, Debug, HasViewportPercentage, PartialEq, ToCss)]
+#[derive(Clone, Debug, PartialEq, ToCss)]
 pub enum MozLength {
     LengthOrPercentageOrAuto(LengthOrPercentageOrAuto),
     ExtremumLength(ExtremumLength),
@@ -1219,7 +1204,7 @@ impl MozLength {
 /// A value suitable for a `max-width` or `max-height` property.
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Clone, Debug, HasViewportPercentage, PartialEq, ToCss)]
+#[derive(Clone, Debug, PartialEq, ToCss)]
 pub enum MaxLength {
     LengthOrPercentageOrNone(LengthOrPercentageOrNone),
     ExtremumLength(ExtremumLength),
diff --git a/components/style/values/specified/mod.rs b/components/style/values/specified/mod.rs
index 642a5ac3053..60b4361cb9a 100644
--- a/components/style/values/specified/mod.rs
+++ b/components/style/values/specified/mod.rs
@@ -102,7 +102,6 @@ impl Eq for SpecifiedUrl {}
 #[cfg(feature = "gecko")]
 impl ComputedValueAsSpecified for SpecifiedUrl {}
 
-no_viewport_percentage!(SpecifiedUrl);
 }
 
 /// Parse an `<integer>` value, handling `calc()` correctly.
@@ -171,7 +170,6 @@ define_numbered_css_keyword_enum! { BorderStyle:
     "outset" => outset = 2,
 }
 
-no_viewport_percentage!(BorderStyle);
 
 impl BorderStyle {
     /// Whether this border style is either none or hidden.
@@ -191,7 +189,6 @@ pub struct Number {
     calc_clamping_mode: Option<AllowedNumericType>,
 }
 
-no_viewport_percentage!(Number);
 
 impl Parse for Number {
     fn parse<'i, 't>(context: &ParserContext, input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i>> {
@@ -296,7 +293,6 @@ pub enum NumberOrPercentage {
     Number(Number),
 }
 
-no_viewport_percentage!(NumberOrPercentage);
 
 impl NumberOrPercentage {
     fn parse_with_clamping_mode<'i, 't>(
@@ -329,7 +325,6 @@ impl Parse for NumberOrPercentage {
 #[derive(Clone, Copy, Debug, PartialEq, PartialOrd, ToCss)]
 pub struct Opacity(Number);
 
-no_viewport_percentage!(Opacity);
 
 impl Parse for Opacity {
     fn parse<'i, 't>(context: &ParserContext, input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i>> {
@@ -389,7 +384,6 @@ impl Integer {
     }
 }
 
-no_viewport_percentage!(Integer);
 
 impl Parse for Integer {
     fn parse<'i, 't>(context: &ParserContext, input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i>> {
@@ -498,7 +492,7 @@ pub type LengthOrPercentageOrNumber = Either<Number, LengthOrPercentage>;
 /// NonNegativeLengthOrPercentage | NonNegativeNumber
 pub type NonNegativeLengthOrPercentageOrNumber = Either<NonNegativeNumber, NonNegativeLengthOrPercentage>;
 
-#[derive(Clone, Debug, HasViewportPercentage, PartialEq)]
+#[derive(Clone, Debug, PartialEq)]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
 /// rect(<top>, <left>, <bottom>, <right>) used by clip and image-region
 pub struct ClipRect {
diff --git a/components/style/values/specified/percentage.rs b/components/style/values/specified/percentage.rs
index 8ab86b720d0..0373d29016e 100644
--- a/components/style/values/specified/percentage.rs
+++ b/components/style/values/specified/percentage.rs
@@ -28,7 +28,6 @@ pub struct Percentage {
     calc_clamping_mode: Option<AllowedNumericType>,
 }
 
-no_viewport_percentage!(Percentage);
 
 impl ToCss for Percentage {
     fn to_css<W>(&self, dest: &mut W) -> fmt::Result
diff --git a/components/style/values/specified/position.rs b/components/style/values/specified/position.rs
index 0adf66e3d76..fb5e22347e8 100644
--- a/components/style/values/specified/position.rs
+++ b/components/style/values/specified/position.rs
@@ -10,7 +10,7 @@
 use cssparser::Parser;
 use parser::{Parse, ParserContext};
 use std::fmt;
-use style_traits::{HasViewportPercentage, ToCss, ParseError};
+use style_traits::{ToCss, ParseError};
 use values::computed::{CalcLengthOrPercentage, LengthOrPercentage as ComputedLengthOrPercentage};
 use values::computed::{Context, Percentage, ToComputedValue};
 use values::generics::position::Position as GenericPosition;
@@ -156,18 +156,6 @@ impl ToCss for Position {
     }
 }
 
-impl<S> HasViewportPercentage for PositionComponent<S> {
-    fn has_viewport_percentage(&self) -> bool {
-        match *self {
-            PositionComponent::Length(ref lop) |
-            PositionComponent::Side(_, Some(ref lop)) => {
-                lop.has_viewport_percentage()
-            },
-            _ => false,
-        }
-    }
-}
-
 impl<S: Parse> Parse for PositionComponent<S> {
     fn parse<'i, 't>(context: &ParserContext, input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i>> {
         Self::parse_quirky(context, input, AllowQuirks::No)
diff --git a/components/style/values/specified/svg.rs b/components/style/values/specified/svg.rs
index 178b6892793..bf57a84301e 100644
--- a/components/style/values/specified/svg.rs
+++ b/components/style/values/specified/svg.rs
@@ -15,7 +15,6 @@ use values::specified::color::RGBAColor;
 /// Specified SVG Paint value
 pub type SVGPaint = generic::SVGPaint<RGBAColor, SpecifiedUrl>;
 
-no_viewport_percentage!(SVGPaint);
 
 /// Specified SVG Paint Kind value
 pub type SVGPaintKind = generic::SVGPaintKind<RGBAColor, SpecifiedUrl>;
diff --git a/components/style/values/specified/time.rs b/components/style/values/specified/time.rs
index 67e5f10dd41..28820158af8 100644
--- a/components/style/values/specified/time.rs
+++ b/components/style/values/specified/time.rs
@@ -16,7 +16,7 @@ use values::computed::time::Time as ComputedTime;
 use values::specified::calc::CalcNode;
 
 /// A time value according to CSS-VALUES § 6.2.
-#[derive(Clone, Copy, Debug, HasViewportPercentage, PartialEq)]
+#[derive(Clone, Copy, Debug, PartialEq)]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
 pub struct Time {
     seconds: CSSFloat,
@@ -25,7 +25,7 @@ pub struct Time {
 }
 
 /// A time unit.
-#[derive(Clone, Copy, Debug, Eq, HasViewportPercentage, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
 pub enum TimeUnit {
     /// `s`
diff --git a/components/style/values/specified/transform.rs b/components/style/values/specified/transform.rs
index e3b3e1e51f7..b40dc58b0a2 100644
--- a/components/style/values/specified/transform.rs
+++ b/components/style/values/specified/transform.rs
@@ -22,7 +22,7 @@ pub type TransformOrigin = GenericTransformOrigin<OriginComponent<X>, OriginComp
 
 /// The specified value of a component of a CSS `<transform-origin>`.
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Clone, Debug, HasViewportPercentage, PartialEq, ToCss)]
+#[derive(Clone, Debug, PartialEq, ToCss)]
 pub enum OriginComponent<S> {
     /// `center`
     Center,
diff --git a/components/style_derive/has_viewport_percentage.rs b/components/style_derive/has_viewport_percentage.rs
deleted file mode 100644
index 18856576fb8..00000000000
--- a/components/style_derive/has_viewport_percentage.rs
+++ /dev/null
@@ -1,42 +0,0 @@
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-use cg;
-use quote;
-use syn;
-use synstructure;
-
-pub fn derive(input: syn::DeriveInput) -> quote::Tokens {
-    let name = &input.ident;
-    let trait_path = &["style_traits", "HasViewportPercentage"];
-    let (impl_generics, ty_generics, mut where_clause) =
-        cg::trait_parts(&input, trait_path);
-
-    let style = synstructure::BindStyle::Ref.into();
-    let match_body = synstructure::each_variant(&input, &style, |bindings, _| {
-        let (first, rest) = match bindings.split_first() {
-            None => return Some(quote!(false)),
-            Some(pair) => pair,
-        };
-        where_clause.add_trait_bound(&first.field.ty);
-        let mut expr = quote!(::style_traits::HasViewportPercentage::has_viewport_percentage(#first));
-        for binding in rest {
-            where_clause.add_trait_bound(&binding.field.ty);
-            expr = quote!(#expr || ::style_traits::HasViewportPercentage::has_viewport_percentage(#binding));
-        }
-        Some(expr)
-    });
-
-    quote! {
-        impl #impl_generics ::style_traits::HasViewportPercentage for #name #ty_generics #where_clause {
-            #[allow(unused_variables, unused_imports)]
-            #[inline]
-            fn has_viewport_percentage(&self) -> bool {
-                match *self {
-                    #match_body
-                }
-            }
-        }
-    }
-}
diff --git a/components/style_derive/lib.rs b/components/style_derive/lib.rs
index f98829e60bf..6e87cc4972a 100644
--- a/components/style_derive/lib.rs
+++ b/components/style_derive/lib.rs
@@ -13,7 +13,6 @@ use proc_macro::TokenStream;
 mod animate;
 mod cg;
 mod compute_squared_distance;
-mod has_viewport_percentage;
 mod to_animated_value;
 mod to_animated_zero;
 mod to_computed_value;
@@ -31,12 +30,6 @@ pub fn derive_compute_squared_distance(stream: TokenStream) -> TokenStream {
     compute_squared_distance::derive(input).to_string().parse().unwrap()
 }
 
-#[proc_macro_derive(HasViewportPercentage)]
-pub fn derive_has_viewport_percentage(stream: TokenStream) -> TokenStream {
-    let input = syn::parse_derive_input(&stream.to_string()).unwrap();
-    has_viewport_percentage::derive(input).to_string().parse().unwrap()
-}
-
 #[proc_macro_derive(ToAnimatedValue)]
 pub fn derive_to_animated_value(stream: TokenStream) -> TokenStream {
     let input = syn::parse_derive_input(&stream.to_string()).unwrap();
diff --git a/components/style_traits/lib.rs b/components/style_traits/lib.rs
index 5de14dfd5e5..0ef1fee83c4 100644
--- a/components/style_traits/lib.rs
+++ b/components/style_traits/lib.rs
@@ -84,7 +84,6 @@ pub mod values;
 pub mod viewport;
 
 pub use values::{Comma, CommaWithSpace, OneOrMoreSeparated, Separator, Space, ToCss};
-pub use viewport::HasViewportPercentage;
 
 /// The error type for all CSS parsing routines.
 pub type ParseError<'i> = cssparser::ParseError<'i, SelectorParseError<'i, StyleParseError<'i>>>;
diff --git a/components/style_traits/viewport.rs b/components/style_traits/viewport.rs
index 97c8c0438bc..97b63aa4915 100644
--- a/components/style_traits/viewport.rs
+++ b/components/style_traits/viewport.rs
@@ -19,66 +19,6 @@ define_css_keyword_enum!(Orientation:
                          "portrait" => Portrait,
                          "landscape" => Landscape);
 
-/// A trait used to query whether this value has viewport units.
-pub trait HasViewportPercentage {
-    /// Returns true if this value has viewport units.
-    fn has_viewport_percentage(&self) -> bool;
-}
-
-/// A macro used to implement HasViewportPercentage trait
-/// for a given type that may never contain viewport units.
-#[macro_export]
-macro_rules! no_viewport_percentage {
-    ($($name: ident),+) => {
-        $(impl $crate::HasViewportPercentage for $name {
-            #[inline]
-            fn has_viewport_percentage(&self) -> bool {
-                false
-            }
-        })+
-    };
-}
-
-no_viewport_percentage!(bool, f32);
-
-impl<T> HasViewportPercentage for Box<T>
-where
-    T: ?Sized + HasViewportPercentage
-{
-    #[inline]
-    fn has_viewport_percentage(&self) -> bool {
-        (**self).has_viewport_percentage()
-    }
-}
-
-impl<T: HasViewportPercentage> HasViewportPercentage for Option<T> {
-    #[inline]
-    fn has_viewport_percentage(&self) -> bool {
-        self.as_ref().map_or(false, T::has_viewport_percentage)
-    }
-}
-
-impl<T: HasViewportPercentage, U> HasViewportPercentage for TypedSize2D<T, U> {
-    #[inline]
-    fn has_viewport_percentage(&self) -> bool {
-        self.width.has_viewport_percentage() || self.height.has_viewport_percentage()
-    }
-}
-
-impl<T: HasViewportPercentage> HasViewportPercentage for Vec<T> {
-    #[inline]
-    fn has_viewport_percentage(&self) -> bool {
-        self.iter().any(T::has_viewport_percentage)
-    }
-}
-
-impl<T: HasViewportPercentage> HasViewportPercentage for [T] {
-    #[inline]
-    fn has_viewport_percentage(&self) -> bool {
-        self.iter().any(T::has_viewport_percentage)
-    }
-}
-
 /// A set of viewport descriptors:
 ///
 /// https://drafts.csswg.org/css-device-adapt/#viewport-desc
diff --git a/tests/unit/style/parsing/value.rs b/tests/unit/style/parsing/value.rs
index 6eeff06b26f..5c1f51dcc4c 100644
--- a/tests/unit/style/parsing/value.rs
+++ b/tests/unit/style/parsing/value.rs
@@ -2,21 +2,12 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use app_units::Au;
 use cssparser::{Parser, ParserInput};
 use style::context::QuirksMode;
 use style::parser::ParserContext;
 use style::stylesheets::{CssRuleType, Origin};
-use style::values::specified::{AbsoluteLength, NoCalcLength, Number, ViewportPercentageLength};
-use style_traits::{PARSING_MODE_ALLOW_ALL_NUMERIC_VALUES, HasViewportPercentage};
-
-#[test]
-fn length_has_viewport_percentage() {
-    let l = NoCalcLength::ViewportPercentage(ViewportPercentageLength::Vw(100.));
-    assert!(l.has_viewport_percentage());
-    let l = NoCalcLength::Absolute(AbsoluteLength::Px(Au(100).to_f32_px()));
-    assert!(!l.has_viewport_percentage());
-}
+use style::values::specified::Number;
+use style_traits::PARSING_MODE_ALLOW_ALL_NUMERIC_VALUES;
 
 #[test]
 fn test_parsing_allo_all_numeric_values() {
diff --git a/tests/unit/style/properties/mod.rs b/tests/unit/style/properties/mod.rs
index 023a9250baf..96b8ffdf617 100644
--- a/tests/unit/style/properties/mod.rs
+++ b/tests/unit/style/properties/mod.rs
@@ -61,4 +61,3 @@ macro_rules! assert_roundtrip_with_context {
 mod background;
 mod scaffolding;
 mod serialization;
-mod viewport;
diff --git a/tests/unit/style/properties/viewport.rs b/tests/unit/style/properties/viewport.rs
deleted file mode 100644
index 205370da8f4..00000000000
--- a/tests/unit/style/properties/viewport.rs
+++ /dev/null
@@ -1,27 +0,0 @@
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-use app_units::Au;
-use style::properties::PropertyDeclaration;
-use style::values::specified::{AbsoluteLength, Length, NoCalcLength, ViewportPercentageLength};
-use style::values::specified::border::BorderSideWidth;
-use style_traits::HasViewportPercentage;
-
-#[test]
-fn has_viewport_percentage_for_specified_value() {
-    //TODO: test all specified value with a HasViewportPercentage impl
-    let pvw = PropertyDeclaration::BorderTopWidth(
-        BorderSideWidth::Length(
-            Length::NoCalc(NoCalcLength::ViewportPercentage(ViewportPercentageLength::Vw(100.)))
-        )
-    );
-    assert!(pvw.has_viewport_percentage());
-
-    let pabs = PropertyDeclaration::BorderTopWidth(
-        BorderSideWidth::Length(
-            Length::NoCalc(NoCalcLength::Absolute(AbsoluteLength::Px(Au(100).to_f32_px())))
-        )
-    );
-    assert!(!pabs.has_viewport_percentage());
-}