Refactor screen/monitor so that gfx::Screen returns monitor object.

ash/wm/workspace/snap_sizer.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/workspace/snap_sizer.h"
 
 #include <cmath>
 
 #include "ash/screen_ash.h"
 #include "ash/wm/window_resizer.h"
@@ skipping 96 matching lines @@
     return gfx::Rect(x, y, mid_x - x, max_y - y);
   }
   int max_x =
       WindowResizer::AlignToGridRoundDown(work_area.right(), grid_size_);
   int x = WindowResizer::AlignToGridRoundUp(max_x - width, grid_size_);
   return gfx::Rect(x , y, max_x - x, max_y - y);
 }
 
 bool SnapSizer::AlongEdge(int x) const {
   // TODO: need to support multi-monitor.
-  gfx::Rect area(gfx::Screen::GetMonitorAreaNearestWindow(window_));
+  gfx::Rect area(gfx::Screen::GetMonitorNearestWindow(window_).bounds());
   return (x <= area.x()) || (x >= area.right() - 1);
 }
 
 }  // namespace internal
 }  // namespace ash