Move MHTML file writing out of the renderer main thread.

content/renderer/render_frame_impl.h

 // Copyright 2013 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 CONTENT_RENDERER_RENDER_FRAME_IMPL_H_
 #define CONTENT_RENDERER_RENDER_FRAME_IMPL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 852 matching lines @@
 #else
   void OnSelectPopupMenuItems(bool canceled,
                               const std::vector<int>& selected_indices);
 #endif
 #endif
 
 #if defined(OS_MACOSX)
   void OnCopyToFindPboard();
 #endif
 
+  // Callback scheduled from OnSerializeAsMHTML for when writing serialized
+  // MHTML to file has been completed in the file thread.
+  void OnWriteMHTMLToDiskComplete(
+      int job_id,
+      std::set<std::string> serialized_resources_uri_digests,
+      base::TimeDelta main_thread_use_time,
+      bool success);
+
   // Requests that the browser process navigates to |url|. If
   // |is_history_navigation_in_new_child| is true, the browser process should
   // look for a matching FrameNavigationEntry in the last committed entry to use
   // instead of |url|.
   void OpenURL(
       const GURL& url,
       bool uses_post,
       const scoped_refptr<ResourceRequestBodyImpl>& resource_request_body,
       const Referrer& referrer,
       blink::WebNavigationPolicy policy,
@@ skipping 418 matching lines @@
       remote_associated_interfaces_;
 
   base::WeakPtrFactory<RenderFrameImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderFrameImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_RENDER_FRAME_IMPL_H_