Add fade to white animation when power button is pressed on Athena

athena/screen/screen_manager_impl.cc

Index: athena/screen/screen_manager_impl.cc
diff --git a/athena/screen/screen_manager_impl.cc b/athena/screen/screen_manager_impl.cc
index 8522acfc7acd30404c8b2ce8aa0d88fad5963769..03dceceaefee8d6a10e1f433ca1e591a1707dab0 100644
--- a/athena/screen/screen_manager_impl.cc
+++ b/athena/screen/screen_manager_impl.cc
@@ -9,6 +9,7 @@
 #include "athena/input/public/accelerator_manager.h"
 #include "athena/screen/background_controller.h"
 #include "athena/screen/screen_accelerator_handler.h"
+#include "athena/screen/screen_animator_impl.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "ui/aura/client/screen_position_client.h"
@@ -199,6 +200,7 @@ class ScreenManagerImpl : public ScreenManager {
   virtual aura::Window* CreateContainer(const ContainerParams& params) OVERRIDE;
   virtual aura::Window* GetContext() OVERRIDE { return root_window_; }
   virtual void SetBackgroundImage(const gfx::ImageSkia& image) OVERRIDE;
+  virtual scoped_ptr<ScreenAnimator> CreateScreenAnimator() OVERRIDE;
 
   aura::Window* root_window_;
   aura::Window* background_window_;
@@ -322,6 +324,10 @@ void ScreenManagerImpl::SetBackgroundImage(const gfx::ImageSkia& image) {
   background_controller_->SetImage(image);
 }
 
+scoped_ptr<ScreenAnimator> ScreenManagerImpl::CreateScreenAnimator() {
+  return scoped_ptr<ScreenAnimator>(new ScreenAnimatorImpl(root_window_));
+}
+
 }  // namespace
 
 ScreenManager::ContainerParams::ContainerParams(const std::string& n,