Explicit animation support

ui/gfx/compositor/layer_animation_delegate.h

Index: ui/gfx/compositor/layer_animation_delegate.h
diff --git a/ui/gfx/compositor/layer_animation_delegate.h b/ui/gfx/compositor/layer_animation_delegate.h
new file mode 100644
index 0000000000000000000000000000000000000000..c6f4fa0e9b0cd0513e3e77e361ff6d924d4836fa
--- /dev/null
+++ b/ui/gfx/compositor/layer_animation_delegate.h
@@ -0,0 +1,32 @@
+// Copyright (c) 2011 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_GFX_COMPOSITOR_LAYER_ANIMATION_DELEGATE_H_
+#define UI_GFX_COMPOSITOR_LAYER_ANIMATION_DELEGATE_H_
+#pragma once
+
+#include "ui/gfx/rect.h"
+#include "ui/gfx/transform.h"
+#include "ui/gfx/compositor/compositor_export.h"
+
+namespace ui {
+
+// LayerAnimation interacts with the Layer using this interface.
+class COMPOSITOR_EXPORT LayerAnimationDelegate {
+ public:
+  virtual void SetBoundsFromAnimation(const gfx::Rect& bounds) = 0;
+  virtual void SetTransformFromAnimation(const Transform& transform) = 0;
+  virtual void SetOpacityFromAnimation(float opacity) = 0;
+  virtual void ScheduleDrawForAnimation() = 0;
+  virtual const gfx::Rect& GetBoundsForAnimation() const = 0;
+  virtual const Transform& GetTransformForAnimation() const = 0;
+  virtual float GetOpacityForAnimation() const = 0;
+
+ protected:
+  virtual ~LayerAnimationDelegate() {}
+};
+
+}  // namespace ui
+
+#endif  // UI_GFX_COMPOSITOR_LAYER_ANIMATION_DELEGATE_H_