Add ExternalPrerenderRequestHandler and related API

chrome/browser/prerender/prerender_manager.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_MANAGER_H_
 #define CHROME_BROWSER_PRERENDER_PRERENDER_MANAGER_H_
 
 #include <list>
 #include <map>
 #include <string>
@@ skipping 133 matching lines @@
   PrerenderHandle* AddPrerenderFromOmnibox(
       const GURL& url,
       content::SessionStorageNamespace* session_storage_namespace,
       const gfx::Size& size);
 
   PrerenderHandle* AddPrerenderFromLocalPredictor(
       const GURL& url,
       content::SessionStorageNamespace* session_storage_namespace,
       const gfx::Size& size);
 
+  PrerenderHandle* AddPrerenderFromExternalRequest(
+      const GURL& url,
+      const content::Referrer& referrer,
+      content::SessionStorageNamespace* session_storage_namespace,
+      const gfx::Size& size);
+
   // If |process_id| and |view_id| refer to a running prerender, destroy
   // it with |final_status|.
   virtual void DestroyPrerenderForRenderView(int process_id,
                                              int view_id,
                                              FinalStatus final_status);
 
   // Cancels all active prerenders.
   void CancelAllPrerenders();
 
   // If |url| matches a valid prerendered page and |params| are compatible, try
@@ skipping 482 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(PrerenderManager);
 };
 
 PrerenderManager* FindPrerenderManagerUsingRenderProcessId(
     int render_process_id);
 
 }  // namespace prerender
 
 #endif  // CHROME_BROWSER_PRERENDER_PRERENDER_MANAGER_H_