Support vendor prefix keyframes rule.

If there are multiple prefixed/non-prefixed @keyframes with the same name;

* non-prefixed rule overrides earlier rules.
* prefixed rule overrides earlier prefixed rules.

components/style/gecko/media_queries.rs

@@ -16,9 +16,9 @@ use gecko_bindings::structs::RawGeckoPresContextOwned;
 use media_queries::MediaType;
 use parser::ParserContext;
 use properties::ComputedValues;
-use std::ascii::AsciiExt;
 use std::fmt::{self, Write};
 use std::sync::Arc;
+use str::starts_with_ignore_ascii_case;
 use string_cache::Atom;
 use style_traits::ToCss;
 use style_traits::viewport::ViewportConstraints;
@@ -340,11 +340,6 @@ impl MediaExpressionValue {
     }
 }
 
-fn starts_with_ignore_ascii_case(string: &str, prefix: &str) -> bool {
-    string.len() > prefix.len() &&
-      string[0..prefix.len()].eq_ignore_ascii_case(prefix)
-}
-
 fn find_feature<F>(mut f: F) -> Option<&'static nsMediaFeature>
     where F: FnMut(&'static nsMediaFeature) -> bool,
 {

components/style/keyframes.rs

@@ -18,7 +18,7 @@ use shared_lock::{SharedRwLock, SharedRwLockReadGuard, Locked, ToCssWithGuard};
 use std::fmt;
 use std::sync::Arc;
 use style_traits::ToCss;
-use stylesheets::{CssRuleType, MemoryHoleReporter, Stylesheet};
+use stylesheets::{CssRuleType, MemoryHoleReporter, Stylesheet, VendorPrefix};
 
 /// A number from 0 to 1, indicating the percentage of the animation when this
 /// keyframe should run.
@@ -239,6 +239,8 @@ pub struct KeyframesAnimation {
     pub steps: Vec<KeyframesStep>,
     /// The properties that change in this animation.
     pub properties_changed: Vec<TransitionProperty>,
+    /// Vendor prefix type the @keyframes has.
+    pub vendor_prefix: Option<VendorPrefix>,
 }
 
 /// Get all the animated properties in a keyframes animation.
@@ -275,11 +277,14 @@ impl KeyframesAnimation {
     ///
     /// Otherwise, this will compute and sort the steps used for the animation,
     /// and return the animation object.
-    pub fn from_keyframes(keyframes: &[Arc<Locked<Keyframe>>], guard: &SharedRwLockReadGuard)
+    pub fn from_keyframes(keyframes: &[Arc<Locked<Keyframe>>],
+                          vendor_prefix: Option<VendorPrefix>,
+                          guard: &SharedRwLockReadGuard)
                           -> Self {
         let mut result = KeyframesAnimation {
             steps: vec![],
             properties_changed: vec![],
+            vendor_prefix: vendor_prefix,
         };
 
         if keyframes.is_empty() {

components/style/str.rs

@@ -7,6 +7,7 @@
 #![deny(missing_docs)]
 
 use num_traits::ToPrimitive;
+use std::ascii::AsciiExt;
 use std::convert::AsRef;
 use std::iter::{Filter, Peekable};
 use std::str::Split;
@@ -144,3 +145,9 @@ pub fn str_join<I, T>(strs: I, join: &str) -> String
         acc
     })
 }
+
+/// Returns true if a given string has a given prefix with case-insensitive match.
+pub fn starts_with_ignore_ascii_case(string: &str, prefix: &str) -> bool {
+    string.len() > prefix.len() &&
+      string[0..prefix.len()].eq_ignore_ascii_case(prefix)
+}

components/style/stylesheets.rs

@@ -36,6 +36,7 @@ use std::cell::Cell;
 use std::fmt;
 use std::sync::Arc;
 use std::sync::atomic::{AtomicBool, Ordering};
+use str::starts_with_ignore_ascii_case;
 use style_traits::ToCss;
 use stylist::FnvHashMap;
 use supports::SupportsCondition;
@@ -529,6 +530,8 @@ pub struct KeyframesRule {
     pub name: Atom,
     /// The keyframes specified for this CSS rule.
     pub keyframes: Vec<Arc<Locked<Keyframe>>>,
+    /// Vendor prefix type the @keyframes has.
+    pub vendor_prefix: Option<VendorPrefix>,
 }
 
 impl ToCssWithGuard for KeyframesRule {
@@ -913,6 +916,15 @@ pub enum State {
     Invalid = 5,
 }
 
+#[derive(Clone, Debug)]
+#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
+/// Vendor prefix.
+pub enum VendorPrefix {
+    /// -moz prefix.
+    Moz,
+    /// -webkit prefix.
+    WebKit,
+}
 
 enum AtRulePrelude {
     /// A @font-face rule prelude.
@@ -923,8 +935,8 @@ enum AtRulePrelude {
     Supports(SupportsCondition),
     /// A @viewport rule prelude.
     Viewport,
-    /// A @keyframes rule, with its animation name.
-    Keyframes(Atom),
+    /// A @keyframes rule, with its animation name and vendor prefix if exists.
+    Keyframes(Atom, Option<VendorPrefix>),
     /// A @page rule prelude.
     Page,
 }
@@ -1111,14 +1123,21 @@ impl<'a, 'b> AtRuleParser for NestedRuleParser<'a, 'b> {
                     Err(())
                 }
             },
-            "keyframes" => {
+            "keyframes" | "-webkit-keyframes" | "-moz-keyframes" => {
+                let prefix = if starts_with_ignore_ascii_case(name, "-webkit-") {
+                    Some(VendorPrefix::WebKit)
+                } else if starts_with_ignore_ascii_case(name, "-moz-") {
+                    Some(VendorPrefix::Moz)
+                } else {
+                    None
+                };
                 let name = match input.next() {
                     Ok(Token::Ident(ref value)) if value != "none" => Atom::from(&**value),
                     Ok(Token::QuotedString(value)) => Atom::from(&*value),
                     _ => return Err(())
                 };
 
-                Ok(AtRuleType::WithBlock(AtRulePrelude::Keyframes(Atom::from(name))))
+                Ok(AtRuleType::WithBlock(AtRulePrelude::Keyframes(Atom::from(name), prefix)))
             },
             "page" => {
                 if cfg!(feature = "gecko") {
@@ -1157,11 +1176,12 @@ impl<'a, 'b> AtRuleParser for NestedRuleParser<'a, 'b> {
                 Ok(CssRule::Viewport(Arc::new(self.shared_lock.wrap(
                    try!(ViewportRule::parse(&context, input))))))
             }
-            AtRulePrelude::Keyframes(name) => {
+            AtRulePrelude::Keyframes(name, prefix) => {
                 let context = ParserContext::new_with_rule_type(self.context, Some(CssRuleType::Keyframes));
                 Ok(CssRule::Keyframes(Arc::new(self.shared_lock.wrap(KeyframesRule {
                     name: name,
                     keyframes: parse_keyframe_list(&context, input, self.shared_lock),
+                    vendor_prefix: prefix,
                 }))))
             }
             AtRulePrelude::Page => {

components/style/stylist.rs

@@ -348,10 +348,17 @@ impl Stylist {
                 CssRule::Keyframes(ref keyframes_rule) => {
                     let keyframes_rule = keyframes_rule.read_with(guard);
                     debug!("Found valid keyframes rule: {:?}", *keyframes_rule);
-                    let animation = KeyframesAnimation::from_keyframes(
-                        &keyframes_rule.keyframes, guard);
-                    debug!("Found valid keyframe animation: {:?}", animation);
-                    self.animations.insert(keyframes_rule.name.clone(), animation);
+
+                    // Don't let a prefixed keyframes animation override a non-prefixed one.
+                    let needs_insertion = keyframes_rule.vendor_prefix.is_none() ||
+                        self.animations.get(&keyframes_rule.name).map_or(true, |rule|
+                            rule.vendor_prefix.is_some());
+                    if needs_insertion {
+                        let animation = KeyframesAnimation::from_keyframes(
+                            &keyframes_rule.keyframes, keyframes_rule.vendor_prefix.clone(), guard);
+                        debug!("Found valid keyframe animation: {:?}", animation);
+                        self.animations.insert(keyframes_rule.name.clone(), animation);
+                    }
                 }
                 CssRule::FontFace(ref rule) => {
                     extra_data.add_font_face(&rule, stylesheet.origin);