Add zoom extension API

chrome/browser/host_zoom_map.h

 // Copyright (c) 2010 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.
 
 // Maps hostnames to custom zoom levels.  Written on the UI thread and read on
 // any thread.  One instance per profile.
 
 #ifndef CHROME_BROWSER_HOST_ZOOM_MAP_H_
 #define CHROME_BROWSER_HOST_ZOOM_MAP_H_
 #pragma once
@@ skipping 32 matching lines @@
   // level, which may be positive (to zoom in) or negative (to zoom out).
   //
   // This may be called on any thread.
   double GetZoomLevel(const GURL& url) const;
 
   // Sets the zoom level for a given url to |level|.  If the level matches the
   // current default zoom level, the host is erased from the saved preferences;
   // otherwise the new value is written out.
   //
   // This should only be called on the UI thread.
-  void SetZoomLevel(const GURL& url, double level);
+  void SetZoomLevel(const GURL& url, int request_id, double level);
 
   // Returns the temporary zoom level that's only valid for the lifetime of
   // the given tab (i.e. isn't saved and doesn't affect other tabs) if it
   // exists, the default zoom level otherwise.
   //
   // This may be called on any thread.
   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
   // tab.
   //
   // This should only be called on the UI thread.
   void SetTemporaryZoomLevel(int render_process_id,
                              int render_view_id,
+                             int request_id,
                              double level);
 
   // Resets all zoom levels.
   //
   // This should only be called on the UI thread.
   void ResetToDefaults();
 
   // NotificationObserver implementation.
   virtual void Observe(NotificationType type,
                        const NotificationSource& source,
@@ skipping 39 matching lines @@
   // notifications from the preference service that we triggered ourself.
   bool updating_preferences_;
 
   NotificationRegistrar registrar_;
   PrefChangeRegistrar pref_change_registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(HostZoomMap);
 };
 
 #endif  // CHROME_BROWSER_HOST_ZOOM_MAP_H_