Refactor MHTMLGenerator to allow getting sending the data to a file descriptor.

content/browser/web_contents/web_contents_impl.cc

 // 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.
 
 #include "content/browser/web_contents/web_contents_impl.h"
 
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
@@ skipping 1911 matching lines @@
   params->set_post_id(post_id);
   params->set_prefer_cache(true);
   if (post_id >= 0)
     params->set_method("POST");
   params->set_prompt(true);
   dlm->DownloadUrl(params.Pass());
 }
 
 void WebContentsImpl::GenerateMHTML(
     const base::FilePath& file,
-    const base::Callback<void(const base::FilePath&, int64)>& callback) {
-  MHTMLGenerationManager::GetInstance()->GenerateMHTML(this, file, callback);
+    const base::Callback<void(int64)>& callback) {
+  MHTMLGenerationManager::GetInstance()->SaveMHTML(this, file, callback);
 }
 
 bool WebContentsImpl::IsActiveEntry(int32 page_id) {
   NavigationEntryImpl* active_entry =
       NavigationEntryImpl::FromNavigationEntry(controller_.GetActiveEntry());
   return (active_entry != NULL &&
           active_entry->site_instance() == GetSiteInstance() &&
           active_entry->GetPageID() == page_id);
 }
 
@@ skipping 1801 matching lines @@
 }
 
 void WebContentsImpl::ClearAllPowerSaveBlockers() {
   for (PowerSaveBlockerMap::iterator i(power_save_blockers_.begin());
        i != power_save_blockers_.end(); ++i)
     STLDeleteValues(&power_save_blockers_[i->first]);
   power_save_blockers_.clear();
 }
 
 }  // namespace content