Trying changes to see the perfomance impact on Mac....

chrome/test/testing_browser_process.cc

 // Copyright (c) 2011 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/test/testing_browser_process.h"
 
 #include "base/string_util.h"
 #include "base/synchronization/waitable_event.h"
 #include "chrome/browser/google/google_url_tracker.h"
 #include "chrome/browser/policy/browser_policy_connector.h"
@@ skipping 40 matching lines @@
 }
 
 base::Thread* TestingBrowserProcess::db_thread() {
   return NULL;
 }
 
 base::Thread* TestingBrowserProcess::cache_thread() {
   return NULL;
 }
 
+WatchDogThread* TestingBrowserProcess::watchdog_thread() {
+  return NULL;
+}
+
 ProfileManager* TestingBrowserProcess::profile_manager() {
   return profile_manager_.get();
 }
 
 void TestingBrowserProcess::SetProfileManager(ProfileManager* profile_manager) {
   profile_manager_.reset(profile_manager);
 }
 
 PrefService* TestingBrowserProcess::local_state() {
   return pref_service_;
@@ skipping 146 matching lines @@
 
 ScopedTestingBrowserProcess::~ScopedTestingBrowserProcess() {
   DCHECK_EQ(browser_process_.get(), g_browser_process);
 
   // TODO(phajdan.jr): Temporary, for http://crbug.com/61062.
   // After the transition is over, we should just
   // reset |g_browser_process| to NULL.
   browser_process_.reset();
   g_browser_process = new TestingBrowserProcess();
 }