Allow animations with inactive observers to reach the Starting state

cc/animation/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/animation/layer_animation_controller.h"
 
 #include <algorithm>
 
 #include "cc/animation/animation.h"
 #include "cc/animation/animation_registrar.h"
@@ skipping 124 matching lines @@
   other_controller->active_animations_.clear();
   active_animations_.swap(other_controller->active_animations_);
   UpdateActivation(NormalActivation);
   set_force_sync();
   other_controller->UpdateActivation(NormalActivation);
   other_controller->set_force_sync();
   other_controller->SetAnimationRegistrar(registrar_);
 }
 
 void LayerAnimationController::Animate(double monotonic_time) {
-  if (!HasActiveValueObserver())
+  if (!HasValueObserver())
     return;
 
   StartAnimationsWaitingForNextTick(monotonic_time);
   StartAnimationsWaitingForStartTime(monotonic_time);
   StartAnimationsWaitingForTargetAvailability(monotonic_time);
   ResolveConflicts(monotonic_time);
   TickAnimations(monotonic_time);
   last_tick_time_ = monotonic_time;
 }
 
@@ skipping 553 matching lines @@
                     OnOpacityAnimated(opacity));
 }
 
 void LayerAnimationController::NotifyObserversTransformAnimated(
     const gfx::Transform& transform) {
   FOR_EACH_OBSERVER(LayerAnimationValueObserver,
                     value_observers_,
                     OnTransformAnimated(transform));
 }
 
+bool LayerAnimationController::HasValueObserver() {
+  if (value_observers_.might_have_observers()) {
+    ObserverListBase<LayerAnimationValueObserver>::Iterator it(
+        value_observers_);
+    return it.GetNext() != NULL;
+  }
+  return false;
+}
+
 bool LayerAnimationController::HasActiveValueObserver() {
   if (value_observers_.might_have_observers()) {
     ObserverListBase<LayerAnimationValueObserver>::Iterator it(
         value_observers_);
     LayerAnimationValueObserver* obs;
     while ((obs = it.GetNext()) != NULL)
       if (obs->IsActive())
         return true;
   }
   return false;
 }
 
 }  // namespace cc