Remove now-unnecessary wrappers around gfx::Screen::GetScreen()

ash/display/root_window_transformers.cc

 // Copyright (c) 2013 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/display/root_window_transformers.h"
 
 #include <cmath>
 
 #include "ash/ash_switches.h"
 #include "ash/display/display_info.h"
 #include "ash/display/display_manager.h"
 #include "ash/host/root_window_transformer.h"
 #include "ash/magnifier/magnification_controller.h"
 #include "ash/shell.h"
 #include "base/command_line.h"
 #include "base/memory/scoped_ptr.h"
 #include "third_party/skia/include/utils/SkMatrix44.h"
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/aura/window_property.h"
 #include "ui/compositor/dip_util.h"
 #include "ui/gfx/display.h"
 #include "ui/gfx/geometry/insets.h"
 #include "ui/gfx/geometry/size_conversions.h"
+#include "ui/gfx/screen.h"
 #include "ui/gfx/transform.h"
 #include "ui/gfx/transform.h"
 
 DECLARE_WINDOW_PROPERTY_TYPE(gfx::Display::Rotation);
 
 namespace ash {
 namespace {
 
 #if defined(OS_WIN)
 DEFINE_WINDOW_PROPERTY_KEY(gfx::Display::Rotation, kRotationPropertyKey,
@@ skipping 238 matching lines @@
   gfx::Insets insets_;
 
   DISALLOW_COPY_AND_ASSIGN(MirrorRootWindowTransformer);
 };
 
 class PartialBoundsRootWindowTransformer : public RootWindowTransformer {
  public:
   PartialBoundsRootWindowTransformer(const gfx::Rect& screen_bounds,
                                      const gfx::Display& display) {
     gfx::Display unified_display =
-        Shell::GetInstance()->GetScreen()->GetPrimaryDisplay();
+        gfx::Screen::GetScreen()->GetPrimaryDisplay();
     DisplayInfo display_info =
         Shell::GetInstance()->display_manager()->GetDisplayInfo(display.id());
     root_bounds_ = gfx::Rect(display_info.bounds_in_native().size());
     float scale = root_bounds_.height() /
                   static_cast<float>(screen_bounds.height()) /
                   unified_display.device_scale_factor();
     transform_.Scale(scale, scale);
     transform_.Translate(-SkIntToMScalar(display.bounds().x()),
                          -SkIntToMScalar(display.bounds().y()));
   }
@@ skipping 32 matching lines @@
                                          mirror_display_info);
 }
 
 RootWindowTransformer* CreateRootWindowTransformerForUnifiedDesktop(
     const gfx::Rect& screen_bounds,
     const gfx::Display& display) {
   return new PartialBoundsRootWindowTransformer(screen_bounds, display);
 }
 
 }  // namespace ash