chromeos: Add support for multiple volume icons.

chrome/browser/chromeos/setting_level_bubble_view.h

Index: chrome/browser/chromeos/setting_level_bubble_view.h
diff --git a/chrome/browser/chromeos/setting_level_bubble_view.h b/chrome/browser/chromeos/setting_level_bubble_view.h
index b1c43ec1d9ac3af38127eb0ce0f7a39396cb50df..519fef8ab9f4371a0b670099ee6aa67251477df2 100644
--- a/chrome/browser/chromeos/setting_level_bubble_view.h
+++ b/chrome/browser/chromeos/setting_level_bubble_view.h
@@ -27,6 +27,9 @@ class SettingLevelBubbleView : public views::View {
   // instance from ResourceBundle).
   void Init(SkBitmap* icon, int level_percent);
 
+  // Change the icon that we're currently displaying.
+  void SetIcon(SkBitmap* icon);
+
   // Set the progress bar to the specified position and redraw it.
   void Update(int level_percent);