predictors: Add browsertest that tests prefetching.

chrome/browser/predictors/resource_prefetch_predictor.cc

 // Copyright 2014 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/predictors/resource_prefetch_predictor.h"
 
 #include <map>
 #include <set>
 #include <utility>
 
@@ skipping 479 matching lines @@
                url.spec());
   if (!prefetch_manager_.get())  // Not enabled.
     return;
 
   BrowserThread::PostTask(
       BrowserThread::IO, FROM_HERE,
       base::Bind(&ResourcePrefetcherManager::MaybeRemovePrefetch,
                  prefetch_manager_, url));
 }
 
+void ResourcePrefetchPredictor::OnPrefetchingFinished(
+    const GURL& main_frame_url) {
+  if (observer_)
+    observer_->OnPrefetchingFinished(main_frame_url);
+}
+
 void ResourcePrefetchPredictor::SetObserverForTesting(TestObserver* observer) {
   observer_ = observer;
 }
 
 void ResourcePrefetchPredictor::Shutdown() {
   if (prefetch_manager_.get()) {
     prefetch_manager_->ShutdownOnUIThread();
     prefetch_manager_ = NULL;
   }
   history_service_observer_.RemoveAll();
@@ skipping 641 matching lines @@
 TestObserver::~TestObserver() {
   predictor_->SetObserverForTesting(nullptr);
 }
 
 TestObserver::TestObserver(ResourcePrefetchPredictor* predictor)
     : predictor_(predictor) {
   predictor_->SetObserverForTesting(this);
 }
 
 }  // namespace predictors