Web Animations API: Deferred computation of interpolated values

Source/core/animation/StringKeyframe.cpp

Index: Source/core/animation/StringKeyframe.cpp
diff --git a/Source/core/animation/StringKeyframe.cpp b/Source/core/animation/StringKeyframe.cpp
index c7124255aece91cecf5e98d473ec7efce8f881a9..43fc83f032aee71e017b985cb625ad49132325a3 100644
--- a/Source/core/animation/StringKeyframe.cpp
+++ b/Source/core/animation/StringKeyframe.cpp
@@ -6,6 +6,7 @@
 #include "core/animation/StringKeyframe.h"
 
 #include "core/animation/Interpolation.h"
+#include "core/animation/LegacyStyleInterpolation.h"
 #include "core/animation/css/CSSAnimations.h"
 #include "core/css/resolver/StyleResolver.h"
 #include "core/rendering/style/RenderStyle.h"
@@ -71,10 +72,14 @@ PassRefPtrWillBeRawPtr<Interpolation> StringKeyframe::PropertySpecificKeyframe::
         return DefaultStyleInterpolation::create(fromCSSValue, toCSSValue, property);
 
     switch (property) {
+    case CSSPropertyBorderBottomWidth:
+    case CSSPropertyBorderLeftWidth:
+    case CSSPropertyBorderRightWidth:
+    case CSSPropertyBorderTopWidth:
+    case CSSPropertyHeight:
     case CSSPropertyLeft:
     case CSSPropertyRight:
     case CSSPropertyWidth:
-    case CSSPropertyHeight:
         if (LengthStyleInterpolation::canCreateFrom(*fromCSSValue) && LengthStyleInterpolation::canCreateFrom(*toCSSValue))
             return LengthStyleInterpolation::create(fromCSSValue, toCSSValue, property);
         break;
@@ -84,13 +89,13 @@ PassRefPtrWillBeRawPtr<Interpolation> StringKeyframe::PropertySpecificKeyframe::
 
     // FIXME: Remove the use of AnimatableValues, RenderStyles and Elements here.
     // FIXME: Remove this cache
-    if (!m_animatableValueCache)
-        m_animatableValueCache = StyleResolver::createAnimatableValueSnapshot(*element, property, fromCSSValue);
-
-    RefPtrWillBeRawPtr<AnimatableValue> to = StyleResolver::createAnimatableValueSnapshot(*element, property, toCSSValue);
-    toStringPropertySpecificKeyframe(end)->m_animatableValueCache = to;
+    if (!m_animatableValueCache && !LegacyStyleInterpolation::interpolationRequiresStyleResolve(*fromCSSValue))
+        m_animatableValueCache = StyleResolver::applyAndSnapshotAnimatableValue(*element, property, *fromCSSValue);
+    StringPropertySpecificKeyframe& endKeyframe = toStringPropertySpecificKeyframe(*end);
+    if (!endKeyframe.m_animatableValueCache && !LegacyStyleInterpolation::interpolationRequiresStyleResolve(*toCSSValue))
+        endKeyframe.m_animatableValueCache = StyleResolver::applyAndSnapshotAnimatableValue(*element, property, *toCSSValue);
 
-    return LegacyStyleInterpolation::create(m_animatableValueCache.get(), to.release(), property);
+    return LegacyStyleInterpolation::create(*fromCSSValue, *toCSSValue, property, *element);
 }
 
 PassOwnPtrWillBeRawPtr<Keyframe::PropertySpecificKeyframe> StringKeyframe::PropertySpecificKeyframe::neutralKeyframe(double offset, PassRefPtr<TimingFunction> easing) const