Prepare for responsive CSS animations.

Source/core/animation/KeyframeEffectModel.cpp

Index: Source/core/animation/KeyframeEffectModel.cpp
diff --git a/Source/core/animation/KeyframeEffectModel.cpp b/Source/core/animation/KeyframeEffectModel.cpp
index fc1f34f527f23625c0e39c8a4883b41ff85e1b13..25402fff6d31775c65b56b8d4ec714864e8ec529 100644
--- a/Source/core/animation/KeyframeEffectModel.cpp
+++ b/Source/core/animation/KeyframeEffectModel.cpp
@@ -33,6 +33,10 @@
 
 #include "core/StylePropertyShorthand.h"
 #include "core/animation/AnimationNode.h"
+#include "core/animation/CompositorAnimations.h"
+#include "core/animation/css/CSSAnimatableValueFactory.h"
+#include "core/animation/css/CSSPropertyEquality.h"
+#include "core/css/resolver/StyleResolver.h"
 #include "platform/animation/AnimationUtilities.h"
 #include "platform/geometry/FloatBox.h"
 #include "platform/transforms/TransformationMatrix.h"
@@ -60,6 +64,55 @@ void KeyframeEffectModelBase::sample(int iteration, double fraction, double iter
     return m_interpolationEffect->getActiveInterpolations(fraction, iterationDuration, result);
 }
 
+void KeyframeEffectModelBase::snapshotCompositableProperties(const Element* element, const RenderStyle& style)
+{
+    ensureKeyframeGroups();
+    for (CSSPropertyID property : CompositorAnimations::CompositableProperties) {
+        if (affects(property)) {
+            for (auto& keyframe : m_keyframeGroups->get(property)->m_keyframes) {
+                auto& stringKeyframe = toStringPropertySpecificKeyframe(*keyframe);
+                if (!stringKeyframe.value()) {
+                    stringKeyframe.setAnimatableValue(CSSAnimatableValueFactory::create(property, style));
+                } else {
+                    ASSERT(!stringKeyframe.getAnimatableValue());
+                    stringKeyframe.setAnimatableValue(StyleResolver::createAnimatableValueSnapshot(const_cast<Element&>(*element), property, *stringKeyframe.value()));
+                }
+            }
+        }
+    }
+}
+
+void KeyframeEffectModelBase::updateNeutralKeyframeAnimatableValues(CSSPropertyID property, PassRefPtrWillBeRawPtr<AnimatableValue> value)
+{
+    ASSERT(CompositorAnimations::isCompositableProperty(property));
+
+    if (!value)
+        return;
+
+    ensureKeyframeGroups();
+    auto& keyframes = m_keyframeGroups->get(property)->m_keyframes;
+
+    ASSERT(keyframes.size() >= 2);
+    if (!toStringPropertySpecificKeyframe(*keyframes[0]).value())

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

ASSERT that start or end is a neutral keyframe
FIXME for other neutral keyframes that are not at start/end

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

Done.

+        toStringPropertySpecificKeyframe(*keyframes[0]).setAnimatableValue(value);
+    if (!toStringPropertySpecificKeyframe(*keyframes[keyframes.size() - 1]).value())
+        toStringPropertySpecificKeyframe(*keyframes[keyframes.size() - 1]).setAnimatableValue(value);
+}
+
+void KeyframeEffectModelBase::setNeutralKeyframeEasings(RefPtrWillBeRawPtr<TimingFunction> easing)
+{
+    ensureKeyframeGroups();
+    for (const auto& entry : *m_keyframeGroups) {
+        auto& keyframes = entry.value->keyframes();
+
+        ASSERT(keyframes.size() >= 2);
+        if (!toStringPropertySpecificKeyframe(*keyframes[0]).value())
+            toStringPropertySpecificKeyframe(*keyframes[0]).setEasing(easing);
+        if (!toStringPropertySpecificKeyframe(*keyframes[keyframes.size() - 1]).value())
+            toStringPropertySpecificKeyframe(*keyframes[keyframes.size() - 1]).setEasing(easing);
+    }
+}
+
 KeyframeEffectModelBase::KeyframeVector KeyframeEffectModelBase::normalizedKeyframes(const KeyframeVector& keyframes)
 {
     double lastOffset = 0;
@@ -140,9 +193,9 @@ void KeyframeEffectModelBase::ensureInterpolationEffect(Element* element) const
 
     for (const auto& entry : *m_keyframeGroups) {
         const PropertySpecificKeyframeVector& keyframes = entry.value->keyframes();
-        ASSERT(keyframes[0]->composite() == AnimationEffect::CompositeReplace);
+        ASSERT(keyframes[0]->composite() == AnimationEffect::CompositeReplace || keyframes[0]->composite() == AnimationEffect::CompositeAdd);
         for (size_t i = 0; i < keyframes.size() - 1; i++) {
-            ASSERT(keyframes[i + 1]->composite() == AnimationEffect::CompositeReplace);
+            ASSERT(keyframes[i + 1]->composite() == AnimationEffect::CompositeReplace || keyframes[i + 1]->composite() == AnimationEffect::CompositeAdd);
             double applyFrom = i ? keyframes[i]->offset() : (-std::numeric_limits<double>::infinity());
             double applyTo = i == keyframes.size() - 2 ? std::numeric_limits<double>::infinity() : keyframes[i + 1]->offset();
             if (applyTo == 1)