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

ui/aura/test/test_screen.cc

 // 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.
 
 #include "ui/aura/test/test_screen.h"
 
 #include "base/logging.h"
 #include "ui/aura/env.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_event_dispatcher.h"
@@ skipping 30 matching lines @@
 
 void TestScreen::SetDeviceScaleFactor(float device_scale_factor) {
   gfx::Rect bounds_in_pixel(display_.GetSizeInPixel());
   display_.SetScaleAndBounds(device_scale_factor, bounds_in_pixel);
   host_->OnHostResized(bounds_in_pixel.size());
 }
 
 void TestScreen::SetDisplayRotation(gfx::Display::Rotation rotation) {
   display_.set_rotation(rotation);
   // TODO(oshima|mukai): Update the display_ as well.
-  host_->SetTransform(GetRotationTransform() * GetUIScaleTransform());
+  host_->SetRootTransform(GetRotationTransform() * GetUIScaleTransform());
 }
 
 void TestScreen::SetUIScale(float ui_scale) {
   ui_scale_ = ui_scale;
   gfx::Rect bounds_in_pixel(display_.GetSizeInPixel());
   gfx::Rect new_bounds = gfx::ToNearestRect(
       gfx::ScaleRect(bounds_in_pixel, 1.0f / ui_scale));
   display_.SetScaleAndBounds(display_.device_scale_factor(), new_bounds);
-  host_->SetTransform(GetRotationTransform() * GetUIScaleTransform());
+  host_->SetRootTransform(GetRotationTransform() * GetUIScaleTransform());
 }
 
 gfx::Transform TestScreen::GetRotationTransform() const {
   gfx::Transform rotate;
   float one_pixel = 1.0f / display_.device_scale_factor();
   switch (display_.rotation()) {
     case gfx::Display::ROTATE_0:
       break;
     case gfx::Display::ROTATE_90:
       rotate.Translate(display_.bounds().height() - one_pixel, 0);
@@ skipping 80 matching lines @@
 
 TestScreen::TestScreen(const gfx::Rect& screen_bounds)
     : host_(NULL),
       ui_scale_(1.0f) {
   static int64 synthesized_display_id = 2000;
   display_.set_id(synthesized_display_id++);
   display_.SetScaleAndBounds(1.0f, screen_bounds);
 }
 
 }  // namespace aura