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

ui/aura/window_tree_host_ozone.h

Index: ui/aura/window_tree_host_ozone.h
diff --git a/ui/aura/window_tree_host_ozone.h b/ui/aura/window_tree_host_ozone.h
index 0e1f469ac1d36e8cbf00134ff40c87e6825a0bd4..0a32da5374eb3729fba8413359f4179d3fa73ff7 100644
--- a/ui/aura/window_tree_host_ozone.h
+++ b/ui/aura/window_tree_host_ozone.h
@@ -32,17 +32,12 @@ class WindowTreeHostOzone : public 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& bounds) 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& event) OVERRIDE;
   virtual void OnDeviceScaleFactorChanged(float device_scale_factor) OVERRIDE;
   virtual void SetCursorNative(gfx::NativeCursor cursor_type) OVERRIDE;