Move creation and ownership of HostZoomMap to content instead of having every embedder do this.

chrome/browser/profiles/off_the_record_profile_impl.h

Index: chrome/browser/profiles/off_the_record_profile_impl.h
===================================================================
--- chrome/browser/profiles/off_the_record_profile_impl.h	(revision 122827)
+++ chrome/browser/profiles/off_the_record_profile_impl.h	(working copy)
@@ -113,7 +113,6 @@
       int renderer_child_id) OVERRIDE;
   virtual net::URLRequestContextGetter* GetRequestContextForMedia() OVERRIDE;
   virtual content::ResourceContext* GetResourceContext() OVERRIDE;
-  virtual content::HostZoomMap* GetHostZoomMap() OVERRIDE;
   virtual content::GeolocationPermissionContext*
       GetGeolocationPermissionContext() OVERRIDE;
   virtual content::SpeechInputPreferences* GetSpeechInputPreferences() OVERRIDE;
@@ -144,9 +143,6 @@
   // We use a non-persistent content settings map for OTR.
   scoped_refptr<HostContentSettingsMap> host_content_settings_map_;
 
-  // Use a separate zoom map for OTR.
-  scoped_refptr<content::HostZoomMap> host_zoom_map_;
-
   // Time we were started.
   Time start_time_;