Web Animations: Plumb compositor group id through animation creation and start/finish notifications

Source/platform/graphics/GraphicsLayer.cpp

Index: Source/platform/graphics/GraphicsLayer.cpp
diff --git a/Source/platform/graphics/GraphicsLayer.cpp b/Source/platform/graphics/GraphicsLayer.cpp
index f9457659d44265de14b8075e3a3cecb6ef2b9e6c..fcb22cf794816f09d020e514f8d04968d283620c 100644
--- a/Source/platform/graphics/GraphicsLayer.cpp
+++ b/Source/platform/graphics/GraphicsLayer.cpp
@@ -1043,15 +1043,14 @@ void GraphicsLayer::paint(GraphicsContext& context, const IntRect& clip)
 }
 
 
-void GraphicsLayer::notifyAnimationStarted(double monotonicTime, WebCompositorAnimation::TargetProperty)
+void GraphicsLayer::notifyAnimationStarted(double monotonicTime, int group)
 {
     if (m_client)
-        m_client->notifyAnimationStarted(this, monotonicTime);
+        m_client->notifyAnimationStarted(this, monotonicTime, group);
 }
 
-void GraphicsLayer::notifyAnimationFinished(double, WebCompositorAnimation::TargetProperty)
+void GraphicsLayer::notifyAnimationFinished(double, int)
 {
-    // Do nothing.
 }
 
 void GraphicsLayer::didScroll()