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

mojo/examples/aura_demo/window_tree_host_mojo.cc

Index: mojo/examples/aura_demo/window_tree_host_mojo.cc
diff --git a/mojo/examples/aura_demo/window_tree_host_mojo.cc b/mojo/examples/aura_demo/window_tree_host_mojo.cc
index b032323b015c726a1389a36e712933f909a64d46..e82c390a32ba0f6aee6872d30c6e10a5d77aa4b6 100644
--- a/mojo/examples/aura_demo/window_tree_host_mojo.cc
+++ b/mojo/examples/aura_demo/window_tree_host_mojo.cc
@@ -71,10 +71,6 @@ void WindowTreeHostMojo::Hide() {
   window()->Hide();
 }
 
-void WindowTreeHostMojo::ToggleFullScreen() {
-  NOTIMPLEMENTED();
-}
-
 gfx::Rect WindowTreeHostMojo::GetBounds() const {
   return bounds_;
 }
@@ -84,15 +80,6 @@ void WindowTreeHostMojo::SetBounds(const gfx::Rect& bounds) {
   native_viewport_->SetBounds(bounds);
 }
 
-gfx::Insets WindowTreeHostMojo::GetInsets() const {
-  NOTIMPLEMENTED();
-  return gfx::Insets();
-}
-
-void WindowTreeHostMojo::SetInsets(const gfx::Insets& insets) {
-  NOTIMPLEMENTED();
-}
-
 gfx::Point WindowTreeHostMojo::GetLocationOnNativeScreen() const {
   return gfx::Point(0, 0);
 }
@@ -110,15 +97,6 @@ bool WindowTreeHostMojo::QueryMouseLocation(gfx::Point* location_return) {
   return false;
 }
 
-bool WindowTreeHostMojo::ConfineCursorToRootWindow() {
-  NOTIMPLEMENTED();
-  return false;
-}
-
-void WindowTreeHostMojo::UnConfineCursor() {
-  NOTIMPLEMENTED();
-}
-
 void WindowTreeHostMojo::PostNativeEvent(
     const base::NativeEvent& native_event) {
   NOTIMPLEMENTED();