style: Store the correct computed values for keywords for sizing properties.

In order to get the correct computed value of these keywords, we have to
make sure we store the correct computed values in sizing properties in
both inline axis and block axis.

-moz-max-content and -moz-min-content should behave as the property's
initial value in block axis. -moz-fit-content and -moz-available are not
supported in block axis, so we also treat them as initial values.

Differential Revision: https://phabricator.services.mozilla.com/D8290

components/style/values/computed/length.rs

@@ -5,9 +5,7 @@
 //! `<length>` computed values, and related ones.
 
 use app_units::Au;
-use logical_geometry::WritingMode;
 use ordered_float::NotNan;
-use properties::LonghandId;
 use std::fmt::{self, Write};
 use std::ops::{Add, Neg};
 use style_traits::{CssWriter, ToCss};
@@ -959,39 +957,6 @@ pub enum ExtremumLength {
     MozAvailable,
 }
 
-impl ExtremumLength {
-    /// Returns whether this size keyword can be used for the given writing-mode
-    /// and property.
-    ///
-    /// TODO: After these values are supported for both axes (and maybe
-    /// unprefixed, see bug 1322780) all this complexity can go away, and
-    /// everything can be derived (no need for uncacheable stuff).
-    fn valid_for(wm: WritingMode, longhand: LonghandId) -> bool {
-        // We only make sense on the inline axis.
-        match longhand {
-            // FIXME(emilio): The flex-basis thing is not quite clear...
-            LonghandId::FlexBasis |
-            LonghandId::MinWidth |
-            LonghandId::MaxWidth |
-            LonghandId::Width => !wm.is_vertical(),
-
-            LonghandId::MinHeight | LonghandId::MaxHeight | LonghandId::Height => wm.is_vertical(),
-
-            LonghandId::MinInlineSize | LonghandId::MaxInlineSize | LonghandId::InlineSize => true,
-            // The block-* properties are rejected at parse-time, so they're
-            // unexpected here.
-            _ => {
-                debug_assert!(
-                    false,
-                    "Unexpected property using ExtremumLength: {:?}",
-                    longhand,
-                );
-                false
-            },
-        }
-    }
-}
-
 /// A value suitable for a `min-width`, `min-height`, `width` or `height`
 /// property.
 ///
@@ -1018,28 +983,11 @@ impl ToComputedValue for specified::MozLength {
 
     #[inline]
     fn to_computed_value(&self, context: &Context) -> MozLength {
-        debug_assert!(
-            context.for_non_inherited_property.is_some(),
-            "Someone added a MozLength to an inherited property? Evil!"
-        );
         match *self {
             specified::MozLength::LengthOrPercentageOrAuto(ref lopoa) => {
                 MozLength::LengthOrPercentageOrAuto(lopoa.to_computed_value(context))
             },
-            specified::MozLength::ExtremumLength(ext) => {
-                context
-                    .rule_cache_conditions
-                    .borrow_mut()
-                    .set_writing_mode_dependency(context.builder.writing_mode);
-                if !ExtremumLength::valid_for(
-                    context.builder.writing_mode,
-                    context.for_non_inherited_property.unwrap(),
-                ) {
-                    MozLength::auto()
-                } else {
-                    MozLength::ExtremumLength(ext)
-                }
-            },
+            specified::MozLength::ExtremumLength(ext) => MozLength::ExtremumLength(ext),
         }
     }
 
@@ -1080,28 +1028,11 @@ impl ToComputedValue for specified::MaxLength {
 
     #[inline]
     fn to_computed_value(&self, context: &Context) -> MaxLength {
-        debug_assert!(
-            context.for_non_inherited_property.is_some(),
-            "Someone added a MaxLength to an inherited property? Evil!"
-        );
         match *self {
             specified::MaxLength::LengthOrPercentageOrNone(ref lopon) => {
                 MaxLength::LengthOrPercentageOrNone(lopon.to_computed_value(context))
             },
-            specified::MaxLength::ExtremumLength(ext) => {
-                context
-                    .rule_cache_conditions
-                    .borrow_mut()
-                    .set_writing_mode_dependency(context.builder.writing_mode);
-                if !ExtremumLength::valid_for(
-                    context.builder.writing_mode,
-                    context.for_non_inherited_property.unwrap(),
-                ) {
-                    MaxLength::none()
-                } else {
-                    MaxLength::ExtremumLength(ext)
-                }
-            },
+            specified::MaxLength::ExtremumLength(ext) => MaxLength::ExtremumLength(ext),
         }
     }
 
@@ -1113,7 +1044,7 @@ impl ToComputedValue for specified::MaxLength {
                     specified::LengthOrPercentageOrNone::from_computed_value(&lopon),
                 )
             },
-            MaxLength::ExtremumLength(ref ext) => specified::MaxLength::ExtremumLength(ext.clone()),
+            MaxLength::ExtremumLength(ext) => specified::MaxLength::ExtremumLength(ext),
         }
     }
 }