Refactor browser window zoom handling and enable zoom icon on all platforms.

chrome/browser/ui/zoom/zoom_observer.h

Index: chrome/browser/ui/zoom/zoom_observer.h
diff --git a/chrome/browser/ui/zoom/zoom_observer.h b/chrome/browser/ui/zoom/zoom_observer.h
index 8ce97ce6031e6590587bcbfbc010a4e3dc788da6..13d78ae5db11aab41a9c08a784e8ac5e57a553a3 100644
--- a/chrome/browser/ui/zoom/zoom_observer.h
+++ b/chrome/browser/ui/zoom/zoom_observer.h
@@ -12,14 +12,8 @@ class TabContents;
 // Interface for objects that wish to be notified of changes in ZoomController.
 class ZoomObserver {
  public:
-  // Notification that the Omnibox zoom icon should change.
-  virtual void OnZoomIconChanged(TabContents* source,
-                                 ZoomController::ZoomIconState state) = 0;
-
   // Notification that the zoom percentage has changed.
-  virtual void OnZoomChanged(TabContents* source,
-                             int zoom_percent,
-                             bool can_show_bubble) = 0;
+  virtual void OnZoomChanged(TabContents* source, bool can_show_bubble) = 0;
 
  protected:
   virtual ~ZoomObserver() {}