Run smooth scroll animations on the compositor when possible

third_party/WebKit/public/platform/WebLayer.h

Index: third_party/WebKit/public/platform/WebLayer.h
diff --git a/third_party/WebKit/public/platform/WebLayer.h b/third_party/WebKit/public/platform/WebLayer.h
index a0e21b27b97afc4ed9c85eadeeb1d3b8d6999549..6ef2535c64630774d818aaf3fd53fd9e8ec67261 100644
--- a/third_party/WebKit/public/platform/WebLayer.h
+++ b/third_party/WebKit/public/platform/WebLayer.h
@@ -160,6 +160,11 @@ public:
     // Pauses all animations with the given id.
     virtual void pauseAnimation(int animationId, double timeOffset) = 0;
 
+    // Aborts all animations with the given id. Different from removeAnimation
+    // in that aborting an animation stops it from affecting both the pending
+    // and active tree.
+    virtual void abortAnimation(int animationId) = 0;
+
     // Returns true if this layer has any active animations - useful for tests.
     virtual bool hasActiveAnimation() = 0;