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

chrome/browser/ui/cocoa/chrome_event_processing_window.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.
 
 #import "chrome/browser/ui/cocoa/chrome_event_processing_window.h"
 
 #include "base/logging.h"
+#import "base/mac/foundation_util.h"
+#import "chrome/browser/app_controller_mac.h"
 #import "chrome/browser/ui/cocoa/chrome_command_dispatcher_delegate.h"
 #import "ui/base/cocoa/user_interface_item_command_handler.h"
 
 @implementation ChromeEventProcessingWindow {
  @private
   base::scoped_nsobject<CommandDispatcher> commandDispatcher_;
   base::scoped_nsobject<ChromeCommandDispatcherDelegate>
       commandDispatcherDelegate_;
   base::scoped_nsprotocol<id<UserInterfaceItemCommandHandler>> commandHandler_;
 }
@@ skipping 53 matching lines @@
 }
 
 // NSWindow overrides (NSUserInterfaceValidations implementation).
 
 - (BOOL)validateUserInterfaceItem:(id<NSValidatedUserInterfaceItem>)item {
   // Since this class implements these selectors, |super| will always say they
   // are enabled. Only use [super] to validate other selectors. If there is no
   // command handler, defer to AppController.
   if ([item action] == @selector(commandDispatch:) ||
       [item action] == @selector(commandDispatchUsingKeyModifiers:)) {
-    return commandHandler_
-               ? [commandHandler_ validateUserInterfaceItem:item window:self]
-               : [[NSApp delegate] validateUserInterfaceItem:item];
+    if (commandHandler_)
+      return [commandHandler_ validateUserInterfaceItem:item window:self];
+
+    AppController* appController =
+        base::mac::ObjCCastStrict<AppController>([NSApp delegate]);
+    return [appController validateUserInterfaceItem:item];
   }
 
   return [super validateUserInterfaceItem:item];
 }
 
 @end  // ChromeEventProcessingWindow