[MacViews] Remove stray/unguarded uses of ui/aura/window.h in cross-platform files

ui/snapshot/screenshot_grabber.h

 // Copyright 2014 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_SNAPSHOT_SCREENSHOT_GRABBER_H_
 #define UI_SNAPSHOT_SCREENSHOT_GRABBER_H_
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/files/file_path.h"
 #include "base/memory/ref_counted_memory.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "base/time/time.h"
-#include "ui/aura/window.h"
 #include "ui/gfx/geometry/rect.h"
+#include "ui/gfx/native_widget_types.h"
 #include "ui/snapshot/screenshot_grabber_observer.h"
 #include "ui/snapshot/snapshot_export.h"
 
 namespace base {
 class TaskRunner;
 }
 
 namespace ui {
 
 // TODO(flackr): Componentize google drive so that we don't need the
@@ skipping 63 matching lines @@
 
   ObserverList<ScreenshotGrabberObserver> observers_;
   base::WeakPtrFactory<ScreenshotGrabber> factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ScreenshotGrabber);
 };
 
 }  // namespace ui
 
 #endif  // UI_SNAPSHOT_SCREENSHOT_GRABBER_H_