Re-revert part of my previous cl r151036 to see if this is the line that caused the regression.

chrome/browser/ui/browser_tab_restore_service_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/ui/browser_tab_restore_service_delegate.h"
 
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_commands.h"
 #include "chrome/browser/ui/browser_finder.h"
 #include "chrome/browser/ui/browser_tabrestore.h"
@@ skipping 85 matching lines @@
   if (browser)
     return browser->tab_restore_service_delegate();
   else
     return NULL;
 }
 
 // static
 TabRestoreServiceDelegate* TabRestoreServiceDelegate::FindDelegateForController(
     const NavigationController* controller,
     int* index) {
-  Browser* browser = browser::FindBrowserForController(controller, index);
+  // TODO(beng): Remove. Used just to see if this function is 2% slower than
+  // FindBrowserForController on Mac 10.6 intl1
+  Browser* browser = browser::FindBrowserWithWebContents(
+      controller->GetWebContents());
+  // Browser* browser = browser::FindBrowserForController(controller, index);
   if (browser)
     return browser->tab_restore_service_delegate();
   else
     return NULL;
 }
 
 // static
 TabRestoreServiceDelegate* TabRestoreServiceDelegate::FindDelegateWithID(
     SessionID::id_type desired_id) {
   Browser* browser = browser::FindBrowserWithID(desired_id);
   if (browser)
     return browser->tab_restore_service_delegate();
   else
     return NULL;
 }