Add Fade-out/Fade-in animation during output-configuration change.

ash/display/output_configurator_animation.h

Index: ash/display/output_configurator_animation.h
diff --git a/ash/display/output_configurator_animation.h b/ash/display/output_configurator_animation.h
new file mode 100644
index 0000000000000000000000000000000000000000..a4652f7b64726927d222f9d066ea0fdaec41f05c
--- /dev/null
+++ b/ash/display/output_configurator_animation.h
@@ -0,0 +1,52 @@
+// 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 ASH_DISPLAY_OUTPUT_CONFIGURATOR_ANIMATION_H_
+#define ASH_DISPLAY_OUTPUT_CONFIGURATOR_ANIMATION_H_
+
+#include <map>
+
+#include "base/callback.h"
+#include "chromeos/display/output_configurator.h"
+
+namespace aura {
+class RootWindow;
+}  // namespace aura
+
+namespace ui {
+class Layer;
+}  // namespace ui
+
+namespace ash {
+namespace internal {
+
+// OutputConfiguratorAnimation provides the visual effects for
+// chromeos::OutputConfigurator, such like fade-out/in during changing
+// the display mode.
+class OutputConfiguratorAnimation
+    : public chromeos::OutputConfigurator::AnimationDelegate {
+ public:
+  OutputConfiguratorAnimation();
+  virtual ~OutputConfiguratorAnimation();
+
+ protected:
+  // chromeos::OutputConfigurator::AnimationDelegate overrides:
+  virtual void WillDisplayModeChange(base::Closure callback) OVERRIDE;
+  virtual void OnDisplayModeChanged() OVERRIDE;
+
+ private:
+  // Clears all hiding layers.  Note that in case that this method is called
+  // during an animation, the method call will cancel all of the animations
+  // and *not* call the registered callback.
+  void ClearHidingLayers();
+
+  std::map<aura::RootWindow*, ui::Layer*> hiding_layers_;
+
+  DISALLOW_COPY_AND_ASSIGN(OutputConfiguratorAnimation);
+};
+
+}  // namespace internal
+}  // namespace ash
+
+#endif  // ASH_DISPLAY_OUTPUT_CONFIGURATION_CONTROLLER_H_