Implicit animations through Layer.

ui/gfx/compositor/layer_animator_delegate.h

+// 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_ANIMATOR_DELEGATE_H_
+#define UI_GFX_COMPOSITOR_LAYER_ANIMATOR_DELEGATE_H_
+#pragma once
+
+#include "ui/gfx/compositor/compositor_export.h"
+
+namespace gfx {
+class Rect;
+}
+
+namespace ui {
+
+class Transform;
+
+// LayerAnimator modifies the Layer using this interface.
+class COMPOSITOR_EXPORT LayerAnimatorDelegate {
+ public:
+  virtual void SetBoundsFromAnimator(const gfx::Rect& bounds) = 0;
+  virtual void SetTransformFromAnimator(const Transform& transform) = 0;
+  virtual void SetOpacityFromAnimator(float opacity) = 0;
+
+ protected:
+  virtual ~LayerAnimatorDelegate() {}
+};
+
+}  // namespace ui
+
+#endif  // UI_GFX_COMPOSITOR_LAYER_H_