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

athena/screen/screen_animator_impl.h

Index: athena/screen/screen_animator_impl.h
diff --git a/athena/screen/screen_animator_impl.h b/athena/screen/screen_animator_impl.h
new file mode 100644
index 0000000000000000000000000000000000000000..bce9e4eb97ad3205115b613223e16655a92a0a58
--- /dev/null
+++ b/athena/screen/screen_animator_impl.h
@@ -0,0 +1,35 @@
+// Copyright 2014 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 ATHENA_SCREEN_SCREEN_ANIMATOR_IMPL_H_
+#define ATHENA_SCREEN_SCREEN_ANIMATOR_IMPL_H_
+
+#include "athena/screen/public/screen_animator.h"
+#include "base/macros.h"
+
+namespace aura {
+class Window;
+}
+
+namespace athena {
+
+// ScreenAnimator implementation.
+class ScreenAnimatorImpl : public ScreenAnimator {
+ public:
+  explicit ScreenAnimatorImpl(aura::Window* root_window);
+  virtual ~ScreenAnimatorImpl();
+
+  // ScreenAnimator:
+  virtual void StartAnimation(AnimationType type,
+                              ui::ImplicitAnimationObserver* observer) OVERRIDE;
+
+ private:
+  aura::Window* root_window_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScreenAnimatorImpl);
+};
+
+}  // namespace athena
+
+#endif  // ATHENA_SCREEN_SCREEN_ANIMATOR_IMPL_H_