Prepare for responsive CSS animations.

Source/core/animation/DeferredLegacyStyleInterpolation.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/animation/DeferredLegacyStyleInterpolation.h"
 
-#include "core/animation/LegacyStyleInterpolation.h"
+#include "core/animation/ActiveAnimations.h"
+#include "core/animation/css/CSSAnimatableValueFactory.h"
 #include "core/css/CSSImageValue.h"
 #include "core/css/CSSPrimitiveValue.h"
 #include "core/css/CSSSVGDocumentValue.h"
 #include "core/css/CSSShadowValue.h"
 #include "core/css/CSSValueList.h"
 #include "core/css/Pair.h"
 #include "core/css/Rect.h"
 #include "core/css/resolver/StyleResolver.h"
 #include "core/css/resolver/StyleResolverState.h"
 
 namespace blink {
 
 void DeferredLegacyStyleInterpolation::apply(StyleResolverState& state) const
 {
-    RefPtrWillBeRawPtr<LegacyStyleInterpolation> innerInterpolation = LegacyStyleInterpolation::create(
-        StyleResolver::createAnimatableValueSnapshot(state, m_id, *m_startCSSValue),
-        StyleResolver::createAnimatableValueSnapshot(state, m_id, *m_endCSSValue),
-        m_id);
-    innerInterpolation->interpolate(m_cachedIteration, m_cachedFraction);
-    innerInterpolation->apply(state);
+    if (m_outdated || !state.element()->activeAnimations() || !state.element()->activeAnimations()->isAnimationStyleChange()) {
+        RefPtrWillBeRawPtr<AnimatableValue> startAnimatableValue = nullptr;
+        RefPtrWillBeRawPtr<AnimatableValue> endAnimatableValue = nullptr;
+
+        // Do checks in this order because calling createAnimatableValueSnapshot modifies the

[dstockwell, 2015/02/05 23:04:52]

In which order?

[dstockwell, 2015/02/05 23:04:52]

In which order?

[shend, 2015/02/06 03:16:25]

Made it clearer in the comment.

+        // style of the StyleResolverState.
+        if (!m_startCSSValue)
+            startAnimatableValue = CSSAnimatableValueFactory::create(m_id, *state.style());
+        if (!m_endCSSValue)
+            endAnimatableValue = CSSAnimatableValueFactory::create(m_id, *state.style());
+
+        if (m_startCSSValue)
+            startAnimatableValue = StyleResolver::createAnimatableValueSnapshot(state, m_id, *m_startCSSValue);
+        if (m_endCSSValue)
+            endAnimatableValue = StyleResolver::createAnimatableValueSnapshot(state, m_id, *m_endCSSValue);
+
+        m_innerInterpolation = LegacyStyleInterpolation::create(startAnimatableValue, endAnimatableValue, m_id);
+
+        m_outdated = false;
+    }
+
+    m_innerInterpolation->interpolate(m_cachedIteration, m_cachedFraction);
+    m_innerInterpolation->apply(state);
 }
 
 bool DeferredLegacyStyleInterpolation::interpolationRequiresStyleResolve(const CSSValue& value)
 {
     // FIXME: should not require resolving styles for initial.
     if (value.isInitialValue() || value.isInheritedValue() || value.isUnsetValue())
         return true;
     if (value.isPrimitiveValue())
         return interpolationRequiresStyleResolve(toCSSPrimitiveValue(value));
     if (value.isValueList())
@@ skipping 96 matching lines @@
 }
 
 void DeferredLegacyStyleInterpolation::trace(Visitor* visitor)
 {
     visitor->trace(m_startCSSValue);
     visitor->trace(m_endCSSValue);
     StyleInterpolation::trace(visitor);
 }
 
 }