app_list: Add sync animation.

ui/app_list/pulsing_block_view.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 UI_APP_LIST_PULSING_BLOCK_VIEW_H_
+#define UI_APP_LIST_PULSING_BLOCK_VIEW_H_
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/timer.h"
+#include "ui/views/view.h"
+
+namespace gfx {
+class Size;
+}
+
+namespace app_list {
+
+// PulsingBlockView shows a pulsing white block via layer animation.
+class PulsingBlockView : public views::View {
+ public:
+  // Constructs a PulsingBlockView of |size|. If |start_delay| is true,
+  // starts the pulsing animation after a random delay.
+  PulsingBlockView(const gfx::Size& size, bool start_delay);
+  virtual ~PulsingBlockView();
+
+ private:
+  void OnStartDelayTimer();
+
+  // views::View overrides:
+  virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
+
+  base::OneShotTimer<PulsingBlockView> start_delay_timer_;
+
+  DISALLOW_COPY_AND_ASSIGN(PulsingBlockView);
+};
+
+}  // namespace app_list
+
+#endif  // UI_APP_LIST_PULSING_BLOCK_VIEW_H_