Switch ContentSettingsObserver to be a RenderFrameObserver instead of a RenderViewObserver

chrome/browser/prerender/prerender_contents.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 CHROME_BROWSER_PRERENDER_PRERENDER_CONTENTS_H_
 #define CHROME_BROWSER_PRERENDER_PRERENDER_CONTENTS_H_
 
-#include <set>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "base/time/time.h"
 #include "base/values.h"
@@ skipping 190 matching lines @@
 
   // Indicates whether this prerendered page can be used for the provided
   // |url| and |session_storage_namespace|.
   bool Matches(
       const GURL& url,
       const content::SessionStorageNamespace* session_storage_namespace) const;
 
   // content::WebContentsObserver implementation.
   virtual void RenderFrameCreated(
       content::RenderFrameHost* render_frame_host) OVERRIDE;
-  virtual void RenderFrameDeleted(
-      content::RenderFrameHost* render_frame_host) OVERRIDE;
   virtual void DidStopLoading(
       content::RenderViewHost* render_view_host) OVERRIDE;
   virtual void DidStartProvisionalLoadForFrame(
       int64 frame_id,
       int64 parent_frame_id,
       bool is_main_frame,
       const GURL& validated_url,
       bool is_error_page,
       bool is_iframe_srcdoc,
       content::RenderViewHost* render_view_host) OVERRIDE;
@@ skipping 202 matching lines @@
 
   typedef std::vector<history::HistoryAddPageArgs> AddPageVector;
 
   // Caches pages to be added to the history.
   AddPageVector add_page_vector_;
 
   // The alias session storage namespace for this prerender.
   scoped_refptr<content::SessionStorageNamespace>
       alias_session_storage_namespace;
 
-  // The RenderFrameHosts for prerender_contents_.
-  std::set<content::RenderFrameHost*> render_frame_hosts_;
-
   DISALLOW_COPY_AND_ASSIGN(PrerenderContents);
 };
 
 }  // namespace prerender
 
 #endif  // CHROME_BROWSER_PRERENDER_PRERENDER_CONTENTS_H_