Backed out changeset 6eb3b0501d00 (bug 1331704)

dom/animation/KeyframeEffectReadOnly.cpp

@@ -286,10 +286,6 @@ KeyframeEffectReadOnly::UpdateProperties(nsStyleContext* aStyleContext)
 
   nsTArray<AnimationProperty> properties = BuildProperties(aStyleContext);
 
-  // We need to update base styles even if any properties are not changed at all
-  // since base styles might have been changed due to parent style changes, etc.
-  EnsureBaseStyles(aStyleContext, properties);
-
   if (mProperties == properties) {
     return;
   }
@@ -397,7 +393,9 @@ KeyframeEffectReadOnly::GetUnderlyingStyle(
     // If we are composing with composite operation that is not 'replace'
     // and we have not composed style for the property yet, we have to get
     // the base style for the property.
-    result = BaseStyle(aProperty);
+    RefPtr<nsStyleContext> styleContext =
+      GetTargetStyleContextWithoutAnimation();
+    result = ResolveBaseStyle(aProperty, styleContext);
   }
 
   return result;
@@ -439,24 +437,38 @@ KeyframeEffectReadOnly::CompositeValue(
 }
 
 void
-KeyframeEffectReadOnly::EnsureBaseStyles(
-  nsStyleContext* aStyleContext,
-  const nsTArray<AnimationProperty>& aProperties)
+KeyframeEffectReadOnly::EnsureBaseStylesForCompositor(
+  const nsCSSPropertyIDSet& aPropertiesToSkip)
 {
   if (!mTarget) {
     return;
   }
 
-  mBaseStyleValues.Clear();
+  RefPtr<nsStyleContext> styleContext;
+
+  for (const AnimationProperty& property : mProperties) {
+    if (!nsCSSProps::PropHasFlags(property.mProperty,
+                                  CSS_PROPERTY_CAN_ANIMATE_ON_COMPOSITOR)) {
+      continue;
+    }
+
+    if (aPropertiesToSkip.HasProperty(property.mProperty)) {
+      continue;
+    }
 
-  for (const AnimationProperty& property : aProperties) {
     for (const AnimationPropertySegment& segment : property.mSegments) {
       if (segment.mFromComposite == dom::CompositeOperation::Replace &&
           segment.mToComposite == dom::CompositeOperation::Replace) {
         continue;
       }
 
-      Unused << ResolveBaseStyle(property.mProperty, aStyleContext);
+      if (!styleContext) {
+        styleContext = GetTargetStyleContextWithoutAnimation();
+      }
+      MOZ_RELEASE_ASSERT(styleContext);
+
+      StyleAnimationValue result =
+        ResolveBaseStyle(property.mProperty, styleContext);
       break;
     }
   }
@@ -483,6 +495,16 @@ KeyframeEffectReadOnly::ComposeStyle(
   // If the progress is null, we don't have fill data for the current
   // time so we shouldn't animate.
   if (computedTiming.mProgress.IsNull()) {
+    // If we are not in-effect, this effect might still be sent to the
+    // compositor and later become in-effect (e.g. if it is in the delay phase,
+    // or, if it is in the end delay phase but with a negative playback rate).
+    // In that case, we might need the base style in order to perform
+    // additive/accumulative animation on the compositor.
+
+    // Note, however, that we don't actually send animations with a negative
+    // playback rate in their end delay phase to the compositor at this stage
+    // (bug 1330498).
+    EnsureBaseStylesForCompositor(aPropertiesToSkip);
     return;
   }
 
@@ -652,6 +674,14 @@ KeyframeEffectReadOnly::ComposeStyle(
       }
     }
   }
+
+  // For properties that can be run on the compositor, we may need to prepare
+  // base styles to send to the compositor even if the current processing
+  // segment for properties does not have either an additive or accumulative
+  // composite mode, and even if the animation is not in-effect. That's because
+  // the animation may later progress to a segment which has an additive or
+  // accumulative composite on the compositor mode.
+  EnsureBaseStylesForCompositor(aPropertiesToSkip);
 }
 
 bool

dom/animation/KeyframeEffectReadOnly.h

@@ -386,9 +386,10 @@ protected:
     nsCSSPropertyID aProperty,
     const RefPtr<AnimValuesStyleRule>& aAnimationRule);
 
-  // Ensure the base styles is available for any properties in |aProperties|.
-  void EnsureBaseStyles(nsStyleContext* aStyleContext,
-                        const nsTArray<AnimationProperty>& aProperties);
+  // Ensure the base styles is available for any properties that can be run on
+  // the compositor and which are not includes in |aPropertiesToSkip|.
+  void EnsureBaseStylesForCompositor(
+    const nsCSSPropertyIDSet& aPropertiesToSkip);
 
   // Returns the base style resolved by |aStyleContext| for |aProperty|.
   StyleAnimationValue ResolveBaseStyle(nsCSSPropertyID aProperty,