[NoStatePrefetch] Add UMA histogram to count prefetch requests

chrome/browser/prerender/prerender_manager.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_manager.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <functional>
@@ skipping 533 matching lines @@
 
   histograms_->RecordPerceivedPageLoadTime(
       origin, perceived_page_load_time, navigation_type, url);
 
   if (navigation_type == NAVIGATION_TYPE_PRERENDERED) {
     histograms_->RecordPercentLoadDoneAtSwapin(
         origin, fraction_plt_elapsed_at_swap_in);
   }
 }
 
+void PrerenderManager::RecordResourcePrefetch(Origin origin,
+                                              bool is_main_resource,
+                                              bool is_no_store) {
+  histograms_->RecordResourcePrefetch(origin, is_main_resource, is_no_store);
+}
+
 // static
 PrerenderManager::PrerenderManagerMode PrerenderManager::GetMode() {
   return mode_;
 }
 
 // static
 void PrerenderManager::SetMode(PrerenderManagerMode mode) {
   mode_ = mode;
 }
 
@@ skipping 751 matching lines @@
   DCHECK_EQ(1u, erased);
 }
 
 void PrerenderManager::SetPrerenderContentsFactoryForTest(
     PrerenderContents::Factory* prerender_contents_factory) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   prerender_contents_factory_.reset(prerender_contents_factory);
 }
 
 }  // namespace prerender