Changes to content/ to facilitate new zoom extension API (work in progress)

content/browser/host_zoom_map_impl.h

Index: content/browser/host_zoom_map_impl.h
diff --git a/content/browser/host_zoom_map_impl.h b/content/browser/host_zoom_map_impl.h
index 155f18e00fb2babd091a352d5df7b2b6974982ce..c1ed9edf412d6e0d28060b8c808ec67b583a3d45 100644
--- a/content/browser/host_zoom_map_impl.h
+++ b/content/browser/host_zoom_map_impl.h
@@ -41,6 +41,12 @@ class CONTENT_EXPORT HostZoomMapImpl : public NON_EXPORTED_BASE(HostZoomMap),
       const std::string& scheme,
       const std::string& host,
       double level) OVERRIDE;
+  virtual void SetTemporaryZoomLevel(int render_process_id,
+                                     int render_view_id,
+                                     const std::string& host,
+                                     double level) OVERRIDE;
+  virtual void EraseTemporaryZoomLevel(int render_process_id,
+                                       int render_view_id) OVERRIDE;
   virtual double GetDefaultZoomLevel() const OVERRIDE;
   virtual void SetDefaultZoomLevel(double level) OVERRIDE;
   virtual scoped_ptr<Subscription> AddZoomLevelChangedCallback(
@@ -54,22 +60,20 @@ class CONTENT_EXPORT HostZoomMapImpl : public NON_EXPORTED_BASE(HostZoomMap),
   double GetTemporaryZoomLevel(int render_process_id,
                                int render_view_id) const;
 
-  // Sets the temporary zoom level that's only valid for the lifetime of this
-  // WebContents.
-  //
-  // This should only be called on the UI thread.
-  void SetTemporaryZoomLevel(int render_process_id,
-                             int render_view_id,
-                             double level);
-
   // NotificationObserver implementation.
   virtual void Observe(int type,
                        const NotificationSource& source,
                        const NotificationDetails& details) OVERRIDE;
 
- private:
+private:
   double GetZoomLevelForHost(const std::string& host) const;
 
+  // Notifies the renderers from this browser context to change the zoom level
+  // for the specified host and scheme.
+  void SendZoomLevelChange(const std::string& scheme,
+                           const std::string& host,
+                           double level);
+
   typedef std::map<std::string, double> HostZoomLevels;
   typedef std::map<std::string, HostZoomLevels> SchemeHostZoomLevels;