Use ash NetworkIconAnimation in NetworkMenuIcon code

ash/system/chromeos/network/network_icon_animation.h

Index: ash/system/chromeos/network/network_icon_animation.h
diff --git a/ash/system/chromeos/network/network_icon_animation.h b/ash/system/chromeos/network/network_icon_animation.h
new file mode 100644
index 0000000000000000000000000000000000000000..a556e876d21ef06e697a221e996967086a828a7f
--- /dev/null
+++ b/ash/system/chromeos/network/network_icon_animation.h
@@ -0,0 +1,42 @@
+// Copyright (c) 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 ASH_SYSTEM_CHROMEOS_NETWORK_NETWORK_ICON_ANIMATION_H_
+#define ASH_SYSTEM_CHROMEOS_NETWORK_NETWORK_ICON_ANIMATION_H_
+
+#include "ash/ash_export.h"
+#include "base/observer_list.h"
+#include "ui/base/animation/animation_delegate.h"
+#include "ui/base/animation/throb_animation.h"
+
+namespace ash {
+namespace network_icon {
+
+class AnimationObserver;
+
+// Single instance class to handle icon animations and keep them in sync.
+class ASH_EXPORT NetworkIconAnimation : public ui::AnimationDelegate {
+ public:
+  NetworkIconAnimation();
+  virtual ~NetworkIconAnimation();
+
+  double GetAnimation();

[jennyz, 2013/01/31 19:16:50]

Please add a comment for GetAnimation method. 

+
+  void AddObserver(AnimationObserver* observer);
+  void RemoveObserver(AnimationObserver* observer);
+
+  // ui::AnimationDelegate implementation.
+  virtual void AnimationProgressed(const ui::Animation* animation) OVERRIDE;
+
+  static NetworkIconAnimation* GetInstance();
+
+ private:
+  ui::ThrobAnimation animation_;
+  ObserverList<AnimationObserver> observers_;
+};
+
+}  // namespace network_icon
+}  // namespace ash
+
+#endif  // ASH_SYSTEM_CHROMEOS_NETWORK_NETWORK_ICON_ANIMATION_H_