[MacViews] Use ChromeCommandDispatcherDelegate to handle keyboard shortcuts.

chrome/browser/ui/views/apps/app_window_native_widget_mac.mm

 // Copyright 2015 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/views/apps/app_window_native_widget_mac.h"
 
 #import <Cocoa/Cocoa.h>
 
 #import "chrome/browser/ui/cocoa/apps/titlebar_background_view.h"
 #import "chrome/browser/ui/views/frame/native_widget_mac_frameless_nswindow.h"
 #include "extensions/browser/app_window/native_app_window.h"
 #import "ui/base/cocoa/window_size_constants.h"
 
 AppWindowNativeWidgetMac::AppWindowNativeWidgetMac(
     views::Widget* widget,
     extensions::NativeAppWindow* native_app_window)
     : NativeWidgetMac(widget), native_app_window_(native_app_window) {
 }
 
 AppWindowNativeWidgetMac::~AppWindowNativeWidgetMac() {
 }
 
-NSWindow* AppWindowNativeWidgetMac::CreateNSWindow(
+NativeWidgetMacNSWindow* AppWindowNativeWidgetMac::CreateNSWindow(
     const views::Widget::InitParams& params) {
   // If the window has a native or colored frame, use the same NSWindow as
   // NativeWidgetMac.
   if (!native_app_window_->IsFrameless()) {
-    NSWindow* ns_window = NativeWidgetMac::CreateNSWindow(params);
+    NativeWidgetMacNSWindow* ns_window =
+        NativeWidgetMac::CreateNSWindow(params);
     if (native_app_window_->HasFrameColor()) {
       [TitlebarBackgroundView
           addToNSWindow:ns_window
             activeColor:native_app_window_->ActiveFrameColor()
           inactiveColor:native_app_window_->InactiveFrameColor()];
     }
     return ns_window;
   }
 
   // NSTexturedBackgroundWindowMask is needed to implement draggable window
   // regions.
   NSUInteger style_mask = NSTexturedBackgroundWindowMask | NSTitledWindowMask |
                           NSClosableWindowMask | NSMiniaturizableWindowMask |
                           NSResizableWindowMask;
   return [[[NativeWidgetMacFramelessNSWindow alloc]
       initWithContentRect:ui::kWindowSizeDeterminedLater
                 styleMask:style_mask
                   backing:NSBackingStoreBuffered
                     defer:NO] autorelease];
 }