[NoStatePrefetch] Do not send responses to renderer in prefetch mode.

chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.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/renderer_host/chrome_resource_dispatcher_host_delegate.h"
 
 #include <stdint.h>
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 704 matching lines @@
         target_info.extension_id = extension_id;
         stream_target_info_[request] = target_info;
         return true;
       }
     }
   }
 #endif
   return false;
 }
 
+bool ChromeResourceDispatcherHostDelegate::ShouldSinkResponse(
+    net::URLRequest* request,
+    ResourceType resource_type) {
+  if (resource_type == content::RESOURCE_TYPE_MAIN_FRAME)
+    return false;
+
+  const ResourceRequestInfo* info = ResourceRequestInfo::ForRequest(request);
+  if (info->GetVisibilityState() != blink::WebPageVisibilityStatePrerender)
+    return false;
+
+  // TODO: Use this when implemented. Could there be a race condition though?
+  // return prerender::PrerenderManager::GetMode() ==
+  //    prerender::PRERENDER_MODE_NOSTATE_PREFETCH;
+  return true;
+}
+
 void ChromeResourceDispatcherHostDelegate::OnStreamCreated(
     net::URLRequest* request,
     std::unique_ptr<content::StreamInfo> stream) {
 #if defined(ENABLE_EXTENSIONS)
   const ResourceRequestInfo* info = ResourceRequestInfo::ForRequest(request);
   std::map<net::URLRequest*, StreamTargetInfo>::iterator ix =
       stream_target_info_.find(request);
   CHECK(ix != stream_target_info_.end());
   bool embedded = info->GetResourceType() != content::RESOURCE_TYPE_MAIN_FRAME;
   content::BrowserThread::PostTask(
@@ skipping 155 matching lines @@
           base::Bind(&ChromeResourceDispatcherHostDelegate::OnAbortedFrameLoad,
                     base::Unretained(this), url, request_loading_time));
       return;
   }
 
   std::string metric_name = (request_loading_time.InMilliseconds() < 100 ?
       "Net.ErrAborted.Fast" : "Net.ErrAborted.Slow");
   rappor::SampleDomainAndRegistryFromGURL(
       g_browser_process->rappor_service(), metric_name, url);
 }