[Offline Pages] Make prerenderer notify us of network progress.

chrome/browser/prerender/prerender_contents.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 "chrome/browser/prerender/prerender_contents.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <functional>
@@ skipping 760 matching lines @@
     prerender_canceler_binding_.Bind(std::move(request));
 }
 
 void PrerenderContents::AddResourceThrottle(
     const base::WeakPtr<PrerenderResourceThrottle>& throttle) {
   resource_throttles_.push_back(throttle);
 }
 
 void PrerenderContents::AddNetworkBytes(int64_t bytes) {
   network_bytes_ += bytes;
+  for (Observer& observer : observer_list_)
+    observer.OnPrerenderNetworkBytesChanged(this);
 }
 
 }  // namespace prerender