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

ash/wm/panels/panel_window_resizer.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/wm/panels/panel_window_resizer.h"
 
 #include "ash/display/window_tree_host_manager.h"
 #include "ash/screen_util.h"
 #include "ash/shelf/shelf.h"
 #include "ash/shelf/shelf_types.h"
@@ skipping 40 matching lines @@
 
 void PanelWindowResizer::Drag(const gfx::Point& location, int event_flags) {
   last_location_ = location;
   ::wm::ConvertPointToScreen(GetTarget()->parent(), &last_location_);
   if (!did_move_or_resize_) {
     did_move_or_resize_ = true;
     StartedDragging();
   }
 
   // Check if the destination has changed displays.
-  gfx::Screen* screen = Shell::GetScreen();
+  gfx::Screen* screen = gfx::Screen::GetScreen();
   const gfx::Display dst_display =
       screen->GetDisplayNearestPoint(last_location_);
   if (dst_display.id() !=
       screen->GetDisplayNearestWindow(panel_container_->GetRootWindow()).id()) {
     // The panel is being dragged to a new display. If the previous container is
     // the current parent of the panel it will be informed of the end of drag
     // when the panel is reparented, otherwise let the previous container know
     // the drag is complete. If we told the panel's parent that the drag was
     // complete it would begin positioning the panel.
     if (GetTarget()->parent() != panel_container_)
@@ skipping 144 matching lines @@
 }
 
 void PanelWindowResizer::UpdateLauncherPosition() {
   if (panel_container_) {
     GetPanelLayoutManager(panel_container_)->shelf()->
         UpdateIconPositionForWindow(GetTarget());
   }
 }
 
 }  // namespace aura