Speculative resource prefetching - Not modify resource_type for MAIN_FRAME requests.

chrome/browser/net/resource_prefetch_predictor_observer.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/net/resource_prefetch_predictor_observer.h"
 
 #include <string>
 
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/resource_request_info.h"
@@ skipping 22 matching lines @@
 
   summary->navigation_id.render_process_id = render_process_id;
   summary->navigation_id.render_view_id = render_view_id;
   summary->navigation_id.main_frame_url = request->first_party_for_cookies();
   summary->navigation_id.creation_time = request->creation_time();
   summary->resource_url = request->original_url();
   summary->resource_type = info->GetResourceType();
   request->GetMimeType(&summary->mime_type);
   summary->was_cached = request->was_cached();
 
-  // We want to rely on the mime_type to determine the resource type since we
-  // dont want types such as PREFETCH, SUB_RESOURCE, etc.
-  summary->resource_type =
-      ResourcePrefetchPredictor::GetResourceTypeFromMimeType(
-          summary->mime_type,
-          summary->resource_type);
+  // Use the mime_type to determine the resource type for subresources since
+  // types such as PREFETCH, SUB_RESOURCE, etc are not useful.
+  if (summary->resource_type != ResourceType::MAIN_FRAME) {
+    summary->resource_type =
+        ResourcePrefetchPredictor::GetResourceTypeFromMimeType(
+            summary->mime_type,
+            summary->resource_type);
+  }
   return true;
 }
 
 }  // namespace
 
 namespace chrome_browser_net {
 
 ResourcePrefetchPredictorObserver::ResourcePrefetchPredictorObserver(
     ResourcePrefetchPredictor* predictor)
-        : predictor_(predictor->AsWeakPtr()) {
+    : predictor_(predictor->AsWeakPtr()) {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 }
 
 ResourcePrefetchPredictorObserver::~ResourcePrefetchPredictorObserver() {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI) ||
         BrowserThread::CurrentlyOn(BrowserThread::IO));
 }
 
 void ResourcePrefetchPredictorObserver::OnRequestStarted(
     net::URLRequest* request,
@@ skipping 54 matching lines @@
 
   BrowserThread::PostTask(
       BrowserThread::UI,
       FROM_HERE,
       base::Bind(&ResourcePrefetchPredictor::RecordUrlResponse,
                  predictor_,
                  summary));
 }
 
 }  // namespace chrome_browser_net