Revert CL 117933003. Re-add resource speculative prefetching code.

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 <string>
 #include <vector>
 
 #include "base/base64.h"
 #include "base/guid.h"
 #include "base/logging.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/component_updater/component_updater_resource_throttle.h"
 #include "chrome/browser/content_settings/host_content_settings_map.h"
 #include "chrome/browser/download/download_request_limiter.h"
 #include "chrome/browser/download/download_resource_throttle.h"
+#include "chrome/browser/net/resource_prefetch_predictor_observer.h"
 #include "chrome/browser/prefetch/prefetch.h"
 #include "chrome/browser/prerender/prerender_manager.h"
 #include "chrome/browser/prerender/prerender_manager_factory.h"
 #include "chrome/browser/prerender/prerender_pending_swap_throttle.h"
 #include "chrome/browser/prerender/prerender_resource_throttle.h"
 #include "chrome/browser/prerender/prerender_tracker.h"
 #include "chrome/browser/prerender/prerender_util.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_io_data.h"
 #include "chrome/browser/renderer_host/safe_browsing_resource_throttle_factory.h"
@@ skipping 374 matching lines @@
                                   resource_type,
                                   throttles);
 #if !defined(DISABLE_NACL)
   if (!is_prerendering) {
     AppendComponentUpdaterThrottles(request,
                                     resource_context,
                                     resource_type,
                                     throttles);
   }
 #endif
+
+  if (io_data->resource_prefetch_predictor_observer()) {
+    io_data->resource_prefetch_predictor_observer()->OnRequestStarted(
+        request, resource_type, info->GetChildID(), info->GetRenderFrameID());
+  }
 }
 
 void ChromeResourceDispatcherHostDelegate::DownloadStarting(
     net::URLRequest* request,
     content::ResourceContext* resource_context,
     int child_id,
     int route_id,
     int request_id,
     bool is_content_initiated,
     bool must_download,
@@ skipping 241 matching lines @@
   GURL webstore_url(extension_urls::GetWebstoreLaunchURL());
   if (request->url().DomainIs(webstore_url.host().c_str())) {
     net::HttpResponseHeaders* response_headers = request->response_headers();
     if (!response_headers->HasHeaderValue("x-frame-options", "deny") &&
         !response_headers->HasHeaderValue("x-frame-options", "sameorigin")) {
       response_headers->RemoveHeader("x-frame-options");
       response_headers->AddHeader("x-frame-options: sameorigin");
     }
   }
 
+  if (io_data->resource_prefetch_predictor_observer())
+    io_data->resource_prefetch_predictor_observer()->OnResponseStarted(request);
+
   // Ignores x-frame-options for the chrome signin UI.
   const std::string request_spec(
       request->first_party_for_cookies().GetOrigin().spec());
 #if defined(OS_CHROMEOS)
   if (request_spec == chrome::kChromeUIOobeURL ||
       request_spec == chrome::kChromeUIChromeSigninURL) {
 #else
   if (request_spec == chrome::kChromeUIChromeSigninURL) {
 #endif
     net::HttpResponseHeaders* response_headers = request->response_headers();
@@ skipping 23 matching lines @@
   AppendChromeSyncGaiaHeader(request, resource_context);
 #endif
 
   // In the Mirror world, Chrome should append a X-Chrome-Connected header to
   // all Gaia requests from a connected profile so Gaia could return a 204
   // response and let Chrome handle the action with native UI. The only
   // exception is requests from gaia webview, since the native profile
   // management UI is built on top of it.
   signin::AppendMirrorRequestHeaderIfPossible(request, redirect_url, io_data);
 
+  if (io_data->resource_prefetch_predictor_observer()) {
+    io_data->resource_prefetch_predictor_observer()->OnRequestRedirected(
+        redirect_url, request);
+  }
+
 #if defined(ENABLE_CONFIGURATION_POLICY)
   if (io_data->policy_header_helper())
     io_data->policy_header_helper()->AddPolicyHeaders(redirect_url, request);
 #endif
 }
 
 // Notification that a request has completed.
 void ChromeResourceDispatcherHostDelegate::RequestComplete(
     net::URLRequest* url_request) {
   // Jump on the UI thread and inform the prerender about the bytes.
   const ResourceRequestInfo* info =
       ResourceRequestInfo::ForRequest(url_request);
   if (url_request && !url_request->was_cached()) {
     BrowserThread::PostTask(BrowserThread::UI,
                             FROM_HERE,
                             base::Bind(&UpdatePrerenderNetworkBytesCallback,
                                        info->GetChildID(),
                                        info->GetRouteID(),
                                        url_request->GetTotalReceivedBytes()));
   }
 }
 
 // static
 void ChromeResourceDispatcherHostDelegate::
     SetExternalProtocolHandlerDelegateForTesting(
     ExternalProtocolHandler::Delegate* delegate) {
   g_external_protocol_handler_delegate = delegate;
 }