Add context to gfx::Screen calls in support of simultaneous desktop+ash

ash/touch/touch_observer_hud.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 "ash/touch/touch_observer_hud.h"
 
 #include "ash/shell_window_ids.h"
 #include "base/stringprintf.h"
 #include "base/utf_string_conversions.h"
 #include "third_party/skia/include/core/SkPath.h"
@@ skipping 24 matching lines @@
   static_cast<int>(SK_ColorWHITE),
   static_cast<int>(SK_ColorBLACK)
 };
 
 class TouchHudCanvas : public views::View {
  public:
   explicit TouchHudCanvas(TouchObserverHUD* owner)
       : owner_(owner),
         path_index_(0),
         color_index_(0) {
-    gfx::Display display = gfx::Screen::GetPrimaryDisplay();
+    gfx::Display display = Shell::GetAshScreen()->GetPrimaryDisplay();
     gfx::Rect bounds = display.bounds();
     size_.set_width(bounds.width() / kScale);
     size_.set_height(bounds.height() / kScale);
   }
 
   virtual ~TouchHudCanvas() {}
 
   void Start(int id, const gfx::Point& point) {
     paths_[path_index_].reset();
     paths_[path_index_].moveTo(SkIntToScalar(point.x() / kScale),
@@ skipping 163 matching lines @@
   return ui::ER_UNHANDLED;
 }
 
 void TouchObserverHUD::OnWidgetClosing(views::Widget* widget) {
   DCHECK_EQ(widget, widget_);
   widget_ = NULL;
 }
 
 }  // namespace internal
 }  // namespace ash