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

athena/screen/public/screen_manager.h

Index: athena/screen/public/screen_manager.h
diff --git a/athena/screen/public/screen_manager.h b/athena/screen/public/screen_manager.h
index 8a82f6c617272a0b59d7d527e61894dd5d3fcd4a..aec966fe6771316581cbc68d7bcf1108b9ca2fd6 100644
--- a/athena/screen/public/screen_manager.h
+++ b/athena/screen/public/screen_manager.h
@@ -8,6 +8,7 @@
 #include <string>
 
 #include "athena/athena_export.h"
+#include "base/memory/scoped_ptr.h"
 
 namespace aura {
 class Window;
@@ -22,6 +23,7 @@ class FocusRules;
 }
 
 namespace athena {
+class ScreenAnimator;
 
 // Mananges basic UI components on the screen such as background, and provide
 // API for other UI components, such as window manager, home card, to
@@ -64,6 +66,9 @@ class ATHENA_EXPORT ScreenManager {
   // Sets the background image.
   virtual void SetBackgroundImage(const gfx::ImageSkia& image) = 0;
 
+  // Creates a ScreenAnimator.
+  virtual scoped_ptr<ScreenAnimator> CreateScreenAnimator() = 0;

[oshima, 2014/08/08 14:56:59]

Sorry if I wasn't clear. I meant

ui::LayerAnimator ScreenManager::GetScreenAnimator();

Animation itself should be in other place (system is fine fornow)

I probably will rework a bit on this API (thinking of an animation object you
can apply), but the above API is good for now.

+
   // Create a focus rules.
   // TODO(oshima): Make this virtual function.
   static wm::FocusRules* CreateFocusRules();