ash: Update launcher overflow chevron.

ash/launcher/overflow_button.h

+// Copyright (c) 2012 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 ASH_LAUNCHER_OVERFLOW_BUTTON_H_
+#define ASH_LAUNCHER_OVERFLOW_BUTTON_H_
+
+#include "ash/wm/shelf_types.h"
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "ui/views/controls/button/custom_button.h"
+
+namespace gfx {
+class ImageSkia;
+}
+
+namespace ash {
+namespace internal {
+
+// Launcher overflow chevron button.
+class OverflowButton : public views::CustomButton {
+ public:
+  explicit OverflowButton(views::ButtonListener* listener);
+  virtual ~OverflowButton();
+
+  void SetShelfAlignment(ShelfAlignment alignment);
+
+ private:
+  void PaintBackground(gfx::Canvas* canvas, int alpha);
+
+  // views::View overrides:
+  virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
+
+  ShelfAlignment alignment_;
+  const gfx::ImageSkia* image_;
+
+  DISALLOW_COPY_AND_ASSIGN(OverflowButton);
+};
+
+}  // namespace internal
+}  // namespace ash
+
+#endif  // ASH_LAUNCHER_OVERFLOW_BUTTON_H_