[Mac] Don't show tooltip when zoom decoration is hidden.

components/zoom/zoom_controller.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 COMPONENTS_ZOOM_ZOOM_CONTROLLER_H_
 #define COMPONENTS_ZOOM_ZOOM_CONTROLLER_H_
 
 #include <memory>
 
 #include "base/compiler_specific.h"
@@ skipping 87 matching lines @@
   ZoomMode zoom_mode() const { return zoom_mode_; }
 
   // Convenience method to get default zoom level. Implemented here for
   // inlining.
   double GetDefaultZoomLevel() const {
     return content::HostZoomMap::GetForWebContents(web_contents())
         ->GetDefaultZoomLevel();
   }
 
   // Convenience method to quickly check if the tab's at default zoom.
-  bool IsAtDefaultZoom() const;
+  // Virtual for testing.
+  virtual bool IsAtDefaultZoom() const;
 
   // Returns which image should be loaded for the current zoom level.
   RelativeZoom GetZoomRelativeToDefault() const;
 
   const ZoomRequestClient* last_client() const { return last_client_.get(); }
 
   void AddObserver(ZoomObserver* observer);
   void RemoveObserver(ZoomObserver* observer);
 
   // Used to set whether the zoom notification bubble can be shown when the
@@ skipping 76 matching lines @@
   content::HostZoomMap* host_zoom_map_;
 
   std::unique_ptr<content::HostZoomMap::Subscription> zoom_subscription_;
 
   DISALLOW_COPY_AND_ASSIGN(ZoomController);
 };
 
 }  // namespace zoom
 
 #endif  // COMPONENTS_ZOOM_ZOOM_CONTROLLER_H_