We don't want to tick animation controllers for non-active layers

cc/layer_animation_controller.cc

 // Copyright 2012 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_animation_controller.h"
 
 #include "cc/active_animation.h"
 #include "cc/animation_registrar.h"
 #include "cc/keyframed_animation_curve.h"
 #include "cc/layer_animation_value_observer.h"
@@ skipping 85 matching lines @@
         removeAnimationsCompletedOnMainThread(controllerImpl);
 
         pushPropertiesToImplThread(controllerImpl);
     }
     controllerImpl->updateActivation();
     updateActivation();
 }
 
 void LayerAnimationController::animate(double monotonicTime, AnimationEventsVector* events)
 {
+    if (!hasActiveObserver())
+        return;
+
     startAnimationsWaitingForNextTick(monotonicTime, events);
     startAnimationsWaitingForStartTime(monotonicTime, events);
     startAnimationsWaitingForTargetAvailability(monotonicTime, events);
     resolveConflicts(monotonicTime);
     tickAnimations(monotonicTime);
     markAnimationsForDeletion(monotonicTime, events);
     startAnimationsWaitingForTargetAvailability(monotonicTime, events);
 
     updateActivation();
 }
@@ skipping 334 matching lines @@
                       OnOpacityAnimated(opacity));
 }
 
 void LayerAnimationController::notifyObserversTransformAnimated(const gfx::Transform& transform)
 {
     FOR_EACH_OBSERVER(LayerAnimationValueObserver,
                       m_observers,
                       OnTransformAnimated(transform));
 }
 
+bool LayerAnimationController::hasActiveObserver()
+{
+    if (m_observers.might_have_observers()) {
+        ObserverListBase<LayerAnimationValueObserver>::Iterator it(m_observers);
+        LayerAnimationValueObserver* obs;
+        while ((obs = it.GetNext()) != NULL)
+            if (obs->IsActive())
+                return true;
+    }
+    return false;
+}
+
 }  // namespace cc