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

ui/aura/root_window_view_mac.h

Index: ui/aura/root_window_view_mac.h
diff --git a/ui/aura/root_window_view_mac.h b/ui/aura/root_window_view_mac.h
deleted file mode 100644
index 6617f36dad9693d804b308404a95db36502a54a5..0000000000000000000000000000000000000000
--- a/ui/aura/root_window_view_mac.h
+++ /dev/null
@@ -1,21 +0,0 @@
-// 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_VIEW_MAC_H_
-#define UI_AURA_ROOT_WINDOW_VIEW_MAC_H_
-
-#import <Cocoa/Cocoa.h>
-
-#include "ui/compositor/compositor.h"
-
-// RootWindowView provides an NSView class that delegates drawing to a
-// ui::Compositor delegate, setting up the NSOpenGLContext as required.
-@interface RootWindowView : NSView {
- @private
-  ui::Compositor* compositor_;
-}
--(void)setCompositor:(ui::Compositor*)compositor;
-@end
-
-#endif  // UI_AURA_ROOT_WINDOW_VIEW_MAC_H_