Move the writing of the MHTML footer to the browser process.

content/renderer/render_frame_impl.cc

 // 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.
 
 #include "content/renderer/render_frame_impl.h"
 
 #include <map>
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 5526 matching lines @@
   if (save_status == MhtmlSaveStatus::SUCCESS) {
     TRACE_EVENT0("page-serialization",
                  "RenderFrameImpl::OnSerializeAsMHTML parts serialization");
     // The returned data can be empty if the frame should be skipped, but this
     // is OK.
     mhtml_contents.emplace_back(WebFrameSerializer::generateMHTMLParts(
         mhtml_boundary, GetWebFrame(), &delegate));
     has_some_data |= !mhtml_contents.back().isEmpty();
   }
 
-  // Generate MHTML footer if needed.
-  if (save_status == MhtmlSaveStatus::SUCCESS && params.is_last_frame) {
-    TRACE_EVENT0("page-serialization",
-                 "RenderFrameImpl::OnSerializeAsMHTML footer");
-    mhtml_contents.emplace_back(
-        WebFrameSerializer::generateMHTMLFooter(mhtml_boundary));
-    has_some_data |= !mhtml_contents.back().isEmpty();
-  }
+  // Note: the MHTML footer is written by the browser process, after the last
+  // frame is serialized by a renderer process.
 
   // Note: we assume RenderFrameImpl::OnWriteMHTMLToDiskComplete and the rest of
   // this function will be fast enough to not need to be accounted for in this
   // metric.
   base::TimeDelta main_thread_use_time = base::TimeTicks::Now() - start_time;
   UMA_HISTOGRAM_TIMES(
       "PageSerialization.MhtmlGeneration.RendererMainThreadTime.SingleFrame",
       main_thread_use_time);
 
   if (save_status == MhtmlSaveStatus::SUCCESS && has_some_data) {
@@ skipping 1284 matching lines @@
   // event target. Potentially a Pepper plugin will receive the event.
   // In order to tell whether a plugin gets the last mouse event and which it
   // is, we set |pepper_last_mouse_event_target_| to null here. If a plugin gets
   // the event, it will notify us via DidReceiveMouseEvent() and set itself as
   // |pepper_last_mouse_event_target_|.
   pepper_last_mouse_event_target_ = nullptr;
 #endif
 }
 
 }  // namespace content