Enable accelerated animations for orphaned layers

cc/layer.cc

 // Copyright 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/layer.h"
 
 #include "cc/animation.h"
 #include "cc/animation_events.h"
 #include "cc/layer_animation_controller.h"
 #include "cc/layer_impl.h"
@@ skipping 724 matching lines @@
     // also being run on the impl thread, there is no need to request a commit to push
     // this value over, so set this value directly rather than calling setTransform.
     m_transform = transform;
 }
 
 bool Layer::IsActive() const
 {
     return true;
 }
 
+bool Layer::IsOrphaned() const
+{
+    return !m_layerTreeHost;
+}
+
 bool Layer::addAnimation(scoped_ptr <Animation> animation)
 {
-    // WebCore currently assumes that accelerated animations will start soon
-    // after the animation is added. However we cannot guarantee that if we do
-    // not have a layerTreeHost that will setNeedsCommit().
-    // Unfortunately, the fix below to guarantee correctness causes performance
-    // regressions on Android, since Android has shipped for a long time
-    // with all animations accelerated. For this reason, we will live with
-    // this bug only on Android until the bug is fixed.
-    // http://crbug.com/129683
-#if !defined(OS_ANDROID)
-    if (!m_layerTreeHost)
+    if (!m_layerAnimationController->animationRegistrar())
         return false;
 
-    if (!m_layerTreeHost->settings().acceleratedAnimationEnabled)
-        return false;
-#endif
-
     m_layerAnimationController->addAnimation(animation.Pass());
     setNeedsCommit();
     return true;
 }
 
 void Layer::pauseAnimation(int animationId, double timeOffset)
 {
     m_layerAnimationController->pauseAnimation(animationId, timeOffset);
     setNeedsCommit();
 }
@@ skipping 26 matching lines @@
     addLayerAnimationEventObserver(m_layerAnimationController.get());
     setNeedsCommit();
 }
 
 scoped_refptr<LayerAnimationController> Layer::releaseLayerAnimationController()
 {
     m_layerAnimationController->removeObserver(this);
     scoped_refptr<LayerAnimationController> toReturn = m_layerAnimationController;
     m_layerAnimationController = LayerAnimationController::create(id());
     m_layerAnimationController->addObserver(this);
+    m_layerAnimationController->setAnimationRegistrar(toReturn->animationRegistrar());
     return toReturn;
 }
 
 bool Layer::hasActiveAnimation() const
 {
     return m_layerAnimationController->hasActiveAnimation();
 }
 
 void Layer::notifyAnimationStarted(const AnimationEvent& event, double wallClockTime)
 {
@@ skipping 31 matching lines @@
 {
     return 0;
 }
 
 void sortLayers(std::vector<scoped_refptr<Layer> >::iterator, std::vector<scoped_refptr<Layer> >::iterator, void*)
 {
     // Currently we don't use z-order to decide what to paint, so there's no need to actually sort Layers.
 }
 
 }  // namespace cc