Mac: Fix SDK 10.11 Compile errors after clang roll in r387792

chrome/browser/chrome_browser_main_mac.mm

 // 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/chrome_browser_main_mac.h"
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/mac/bundle_locations.h"
+#import "base/mac/foundation_util.h"
 #include "base/mac/mac_util.h"
 #include "base/mac/scoped_nsobject.h"
 #include "base/path_service.h"
 #include "base/thread_task_runner_handle.h"
 #import "chrome/browser/app_controller_mac.h"
 #include "chrome/browser/apps/app_shim/app_shim_host_manager_mac.h"
 #include "chrome/browser/browser_process.h"
 #import "chrome/browser/chrome_browser_application_mac.h"
 #include "chrome/browser/mac/install_from_dmg.h"
 #import "chrome/browser/mac/keystone_glue.h"
@@ skipping 174 matching lines @@
   KeystoneGlue* glue = [KeystoneGlue defaultKeystoneGlue];
   if (glue && ![glue isRegisteredAndActive]) {
     // If profile loading has failed, we still need to handle other tasks
     // like marking of the product as active.
     [glue updateProfileCountsWithNumProfiles:0
                          numSignedInProfiles:0];
   }
 }
 
 void ChromeBrowserMainPartsMac::DidEndMainMessageLoop() {
-  AppController* appController = [NSApp delegate];
+  AppController* appController =
+      base::mac::ObjCCastStrict<AppController>([NSApp delegate]);
   [appController didEndMainMessageLoop];
 }