Web Animations CSS: Start running animations on the compositor

Source/core/animation/CompositorAnimations.cpp

Index: Source/core/animation/CompositorAnimations.cpp
diff --git a/Source/core/animation/CompositorAnimations.cpp b/Source/core/animation/CompositorAnimations.cpp
index 260a736d9f38e9f9cf54bf9f12237b104dcc4fef..728bf360866e564f76a4758ee1f5e8b792ed3eea 100644
--- a/Source/core/animation/CompositorAnimations.cpp
+++ b/Source/core/animation/CompositorAnimations.cpp
@@ -123,7 +123,7 @@ PassRefPtr<TimingFunction> CompositorAnimationsTimingFunctionReverser::reverse(c
 // CompositorAnimations public API
 // -----------------------------------------------------------------------
 
-bool CompositorAnimations::isCandidateForCompositorAnimation(const Timing& timing, const AnimationEffect& effect)
+bool CompositorAnimations::isCandidateForCompositorAnimations(const Timing& timing, const AnimationEffect& effect)
 {
     const KeyframeAnimationEffect& keyframeEffect = *toKeyframeAnimationEffect(&effect);
 
@@ -131,15 +131,16 @@ bool CompositorAnimations::isCandidateForCompositorAnimation(const Timing& timin
         && CompositorAnimationsImpl::isCandidateForCompositor(timing, keyframeEffect.getFrames());
 }
 
-bool CompositorAnimations::canStartCompositorAnimation(const Element& element)
+bool CompositorAnimations::canStartCompositorAnimations(const Element& element)
 {
     return element.renderer() && element.renderer()->compositingState() == PaintsIntoOwnBacking;
 }
 
-void CompositorAnimations::startCompositorAnimation(const Element& element, const Timing& timing, const AnimationEffect& effect, Vector<int>& startedAnimationIds)
+bool CompositorAnimations::startCompositorAnimations(const Element& element, const Timing& timing, const AnimationEffect& effect, Vector<int>& startedAnimationIds)
 {
-    ASSERT(isCandidateForCompositorAnimation(timing, effect));
-    ASSERT(canStartCompositorAnimation(element));
+    ASSERT(startedAnimationIds.isEmpty());
+    ASSERT(isCandidateForCompositorAnimations(timing, effect));
+    ASSERT(canStartCompositorAnimations(element));
 
     const KeyframeAnimationEffect& keyframeEffect = *toKeyframeAnimationEffect(&effect);
 
@@ -147,19 +148,27 @@ void CompositorAnimations::startCompositorAnimation(const Element& element, cons
     ASSERT(layer);
     ASSERT(layer->renderBox());
 
-    // FIXME: Should we check in some way if there is an animation already created?
     Vector<OwnPtr<blink::WebAnimation> > animations;
     CompositorAnimationsImpl::getCompositorAnimations(timing, keyframeEffect, animations, layer->renderBox()->pixelSnappedBorderBoxRect().size());
     for (size_t i = 0; i < animations.size(); ++i) {
-        startedAnimationIds.append(animations[i]->id());
-        layer->compositedLayerMapping()->mainGraphicsLayer()->addAnimation(animations[i].release());
+        int id = animations[i]->id();
+        if (!layer->compositedLayerMapping()->mainGraphicsLayer()->addAnimation(animations[i].release())) {
+            // FIXME: We should know ahead of time whether these animations can be started.

[ajuma, 2013/11/18 21:21:17]

Note that for the old path, there's logic to avoid sending pixel-moving filter
animations to the compositor (e.g. see
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...).
We'll need something equivalent for the new path too.

[dstockwell, 2013/11/18 21:34:03]

Thanks for taking a look. We have the same logic here:
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...

+            for (size_t j = 0; j < startedAnimationIds.size(); ++j)
+                cancelCompositorAnimations(element, startedAnimationIds[j]);
+            startedAnimationIds.clear();
+            return false;
+        }
+        startedAnimationIds.append(id);
     }
+    return true;
 }
 
-void CompositorAnimations::cancelCompositorAnimation(const Element& element, int id)
+void CompositorAnimations::cancelCompositorAnimations(const Element& element, int id)
 {
-    // FIXME: Implement.
-    ASSERT_NOT_REACHED();
+    if (!element.renderer() || element.renderer()->compositingState() != PaintsIntoOwnBacking)
+        return;
+    toRenderBoxModelObject(element.renderer())->layer()->compositedLayerMapping()->mainGraphicsLayer()->removeAnimation(id);
 }
 
 // -----------------------------------------------------------------------
@@ -246,7 +255,6 @@ bool CompositorAnimationsImpl::isCandidateForCompositor(const KeyframeAnimationE
 
 bool CompositorAnimationsImpl::isCandidateForCompositor(const Timing& timing, const KeyframeAnimationEffect::KeyframeVector& frames)
 {
-
     CompositorTiming out;
     if (!convertTimingForCompositor(timing, out))
         return false;