Introdcue AshWindowTreeHost and move ash/chrome specific code in WTH to ash.

ui/views/widget/desktop_aura/desktop_window_tree_host_x11.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_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_WINDOW_TREE_HOST_X11_H_
 #define UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_WINDOW_TREE_HOST_X11_H_
 
 #include <X11/extensions/shape.h>
 #include <X11/Xlib.h>
 
@@ skipping 115 matching lines @@
   virtual void FlashFrame(bool flash_frame) OVERRIDE;
   virtual void OnRootViewLayout() const OVERRIDE;
   virtual void OnNativeWidgetFocus() OVERRIDE;
   virtual void OnNativeWidgetBlur() OVERRIDE;
   virtual bool IsAnimatingClosed() const OVERRIDE;
 
   // Overridden from aura::WindowTreeHost:
   virtual gfx::AcceleratedWidget GetAcceleratedWidget() OVERRIDE;
   virtual void Show() OVERRIDE;
   virtual void Hide() OVERRIDE;
-  virtual void ToggleFullScreen() OVERRIDE;
   virtual gfx::Rect GetBounds() const OVERRIDE;
   virtual void SetBounds(const gfx::Rect& bounds) OVERRIDE;
-  virtual gfx::Insets GetInsets() const OVERRIDE;
-  virtual void SetInsets(const gfx::Insets& insets) OVERRIDE;
   virtual gfx::Point GetLocationOnNativeScreen() const OVERRIDE;
   virtual void SetCapture() OVERRIDE;
   virtual void ReleaseCapture() OVERRIDE;
   virtual bool QueryMouseLocation(gfx::Point* location_return) OVERRIDE;
-  virtual bool ConfineCursorToRootWindow() OVERRIDE;
-  virtual void UnConfineCursor() OVERRIDE;
   virtual void PostNativeEvent(const base::NativeEvent& native_event) OVERRIDE;
   virtual void OnDeviceScaleFactorChanged(float device_scale_factor) OVERRIDE;
   virtual void SetCursorNative(gfx::NativeCursor cursor) OVERRIDE;
   virtual void MoveCursorToNative(const gfx::Point& location) OVERRIDE;
   virtual void OnCursorVisibilityChangedNative(bool show) OVERRIDE;
 
   // Overridden frm ui::EventSource
   virtual ui::EventProcessor* GetEventProcessor() OVERRIDE;
 
 private:
@@ skipping 141 matching lines @@
   // attention to the window or completely ignore the hint. We stop flashing
   // the frame when |xwindow_| gains focus or handles a mouse button event.
   bool urgency_hint_set_;
 
   DISALLOW_COPY_AND_ASSIGN(DesktopWindowTreeHostX11);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_WINDOW_TREE_HOST_X11_H_