[Cleanup] Remove mac code from aura/ash/views

ui/aura/root_window_mac.h

-// 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.
-
-#ifndef UI_AURA_ROOT_WINDOW_MAC_H_
-#define UI_AURA_ROOT_WINDOW_MAC_H_
-
-#import <Cocoa/Cocoa.h>
-
-namespace aura {
-class RootWindowHostMacDelegate;
-}  // aura
-
-// RootWindow routes NSWindow events back to the RootWindowHost for dispatch
-// to the Aura event handling system.
-@interface RootWindowMac : NSWindow {
- @private
-  // Weak.  May be NULL.  The host delegate acts as a conduit for event routing
-  // back to the host.
-  aura::RootWindowHostMacDelegate* hostDelegate_;
-}
-
-// Designated initializer.
-- (id)initWithContentRect:(NSRect)contentRect
-                styleMask:(NSUInteger)windowStyle
-                  backing:(NSBackingStoreType)bufferingType
-                    defer:(BOOL)deferCreation;
-
-// Sets the |hostDelegate_|
-- (void)setHostDelegate:(aura::RootWindowHostMacDelegate*)hostDelegate;
-
-// Overrides main event dispatch to route NSWindow events to host delegate.
-- (void)sendEvent:(NSEvent*)event;
-
-@end
-
-#endif  // UI_AURA_ROOT_WINDOW_MAC_H_