Fix black background when locking with fullscreen window:

ui/compositor/layer_animator.h

 // Copyright (c) 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.
 
 #ifndef UI_COMPOSITOR_LAYER_ANIMATOR_H_
 #define UI_COMPOSITOR_LAYER_ANIMATOR_H_
 
 #include <deque>
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/memory/linked_ptr.h"
 #include "base/memory/ref_counted.h"
 #include "base/observer_list.h"
 #include "base/time.h"
 #include "ui/base/animation/animation_container_element.h"
+#include "ui/base/animation/animation_container_test_helper.h"
 #include "ui/base/animation/tween.h"
 #include "ui/compositor/compositor_export.h"
 #include "ui/compositor/layer_animation_element.h"
 
 namespace gfx {
 class Rect;
 class Transform;
 }
 
 namespace ui {
 class Animation;
 class Layer;
 class LayerAnimationSequence;
 class LayerAnimationDelegate;
 class LayerAnimationObserver;
 class ScopedLayerAnimationSettings;
 
+namespace internal {
+
+// Returns the AnimationContainer we're added to.
+COMPOSITOR_EXPORT ui::AnimationContainer* GetLayerAnimationContainer();
+
+} // namespace internal
+
 // When a property of layer needs to be changed it is set by way of
 // LayerAnimator. This enables LayerAnimator to animate property changes.
 // NB: during many tests, set_disable_animations_for_test is used and causes
 // all animations to complete immediately. The layer animation is ref counted
 // so that if its owning layer is deleted (and the owning layer is only other
 // class that should ever hold a ref ptr to a LayerAnimator), the animator can
 // ensure that it is not disposed of until it finishes executing. It does this
 // by holding a reference to itself for the duration of methods for which it
 // must guarantee that |this| is valid.
 class COMPOSITOR_EXPORT LayerAnimator
@@ skipping 312 matching lines @@
   // Observers are notified when layer animations end, are scheduled or are
   // aborted.
   ObserverList<LayerAnimationObserver> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerAnimator);
 };
 
 }  // namespace ui
 
 #endif  // UI_COMPOSITOR_LAYER_ANIMATOR_H_