Prepare to use gfx::RenderText in views::Label.

ui/app_list/views/cached_label.h

-// Copyright 2013 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_APP_LIST_VIEWS_CACHED_LABEL_H_
-#define UI_APP_LIST_VIEWS_CACHED_LABEL_H_
-
-#include "ui/gfx/image/image_skia.h"
-#include "ui/views/controls/label.h"
-#include "ui/views/view.h"
-
-namespace gfx {
-class Canvas;
-}
-
-namespace app_list {
-
-// Subclass of views::Label that caches the rendered text in an ImageSkia.
-class CachedLabel : public views::Label {
- public:
-  CachedLabel();
-
-  // Have the next call to OnPaint() update the backing image.
-  void Invalidate() { needs_repaint_ = true; }
-
-  // Calls the base label's OnPaint() to paint into a backing image.
-  void PaintToBackingImage();
-
-#if defined(OS_WIN)
-  // views::View overrides.
-  virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
-#endif
-
- private:
-  bool needs_repaint_;
-  gfx::ImageSkia image_;
-};
-
-}  // namespace app_list
-
-#endif  // UI_APP_LIST_VIEWS_CACHED_LABEL_H_