Implement animations for Independent CSS Transform Properties

Source/core/animation/KeyframeEffect.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 227 matching lines @@
 }
 #endif
 
 bool KeyframeEffect::isCandidateForAnimationOnCompositor(double animationPlaybackRate) const
 {
     if (!model()
         || !m_target
         || (m_target->computedStyle() && m_target->computedStyle()->hasMotionPath()))
         return false;
 
+    // Put transform operations on compositor iff that single transform
+    // is on ComputedStyle and that is the one being animated because we need
+    // to order the transforms correctly
+    if (m_target->computedStyle()) {
+        unsigned transformCounts = 0;
+        if (m_target->computedStyle()->rotate())
+            transformCounts++;
+        if (m_target->computedStyle()->scale())
+            transformCounts++;
+        if (m_target->computedStyle()->translate())
+            transformCounts++;
+        if (m_target->computedStyle()->hasTransformOperations())
+            transformCounts++;
+        if (transformCounts > 1)
+            return false;
+    }

[Eric Willigers, 2015/06/23 06:50:48]

Does KeyframeEffect::applyEffects() need the same test, to
cancelAnimationOnCompositor in the case a translate/rotate/scale/transform is
set after the composited animation has started?

If so, move the test into a new method.

[soonm, 2015/06/24 00:26:44]

Will move into new methods in a new patch with compositor animations

+
     return CompositorAnimations::instance()->isCandidateForAnimationOnCompositor(specifiedTiming(), *m_target, animation(), *model(), animationPlaybackRate);
 }
 
 bool KeyframeEffect::maybeStartAnimationOnCompositor(int group, double startTime, double currentTime, double animationPlaybackRate)
 {
     ASSERT(!hasActiveAnimationsOnCompositor());
     if (!isCandidateForAnimationOnCompositor(animationPlaybackRate))
         return false;
     if (!CompositorAnimations::instance()->canStartAnimationOnCompositor(*m_target))
         return false;
@@ skipping 74 matching lines @@
 
 DEFINE_TRACE(KeyframeEffect)
 {
     visitor->trace(m_target);
     visitor->trace(m_model);
     visitor->trace(m_sampledEffect);
     AnimationEffect::trace(visitor);
 }
 
 } // namespace blink