Not for review: Enable accelerated animations for orphaned layers

cc/layer_animation_controller.cc

Index: cc/layer_animation_controller.cc
diff --git a/cc/layer_animation_controller.cc b/cc/layer_animation_controller.cc
index 8efcc4f93c57db5698b7bbd850ac98dc033f09a6..c2751875bb6ef169914dc752cb17112a32128d23 100644
--- a/cc/layer_animation_controller.cc
+++ b/cc/layer_animation_controller.cc
@@ -20,6 +20,7 @@ LayerAnimationController::LayerAnimationController(int id)
     , m_id(id)
     , m_registrar(0)
     , m_isActive(false)
+    , m_orphanWaitStatus(NeverWaitedForLayout)
 {
 }
 
@@ -130,6 +131,8 @@ void LayerAnimationController::animate(double monotonicTime, AnimationEventsVect
 void LayerAnimationController::addAnimation(scoped_ptr<Animation> animation)
 {
     m_activeAnimations.push_back(animation.Pass());
+    if ((m_orphanWaitStatus == NeverWaitedForLayout) && !hasNonOrphanedObserver())
+        m_orphanWaitStatus = WaitingForLayout;
     updateActivation();
 }
 
@@ -207,6 +210,19 @@ void LayerAnimationController::removeObserver(LayerAnimationValueObserver* obser
     m_observers.RemoveObserver(observer);
 }
 
+bool LayerAnimationController::hasNonOrphanedObserver()
+{
+    if (m_observers.might_have_observers()) {
+        ObserverListBase<LayerAnimationValueObserver>::Iterator it(m_observers);
+        LayerAnimationValueObserver* obs;
+        while ((obs = it.GetNext()) != NULL) {
+            if (!obs->IsOrphaned())
+                return true;
+        }
+    }
+    return false;
+}
+
 void LayerAnimationController::pushNewAnimationsToImplThread(LayerAnimationController* controllerImpl) const
 {
     // Any new animations owned by the main thread's controller are cloned and adde to the impl thread's controller.