[SPv2] Decomposite otherwise-compositable animations that paint nothing.

third_party/WebKit/Source/core/animation/DocumentAnimations.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 49 matching lines @@
          document.timeline().needsAnimationTimingUpdate();
 }
 
 void DocumentAnimations::updateAnimationTimingIfNeeded(Document& document) {
   if (needsAnimationTimingUpdate(document))
     updateAnimationTiming(document, TimingUpdateOnDemand);
 }
 
 void DocumentAnimations::updateAnimations(
     Document& document,
-    DocumentLifecycle::LifecycleState requiredLifecycleState) {
+    DocumentLifecycle::LifecycleState requiredLifecycleState,
+    Optional<CompositorElementIdSet>& compositedElementIds) {
   DCHECK(document.lifecycle().state() >= requiredLifecycleState);
 
-  if (document.compositorPendingAnimations().update()) {
+  if (document.compositorPendingAnimations().update(compositedElementIds)) {
     DCHECK(document.view());
     document.view()->scheduleAnimation();
   }
 
   document.timeline().scheduleNextService();
 }
 
 }  // namespace blink