Fix code around display overscan settings.

ash/display/multi_display_manager.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/display/multi_display_manager.h"
 
 #include <string>
 #include <vector>
 
 #include "ash/display/display_controller.h"
@@ skipping 179 matching lines @@
       new_displays.push_back(*internal_display_.get());
     }
   } else {
     new_displays = updated_displays;
   }
 
   for (DisplayList::iterator iter = new_displays.begin();
        iter != new_displays.end(); ++iter) {
     std::map<int64, gfx::Insets>::const_iterator overscan_insets =
         overscan_mapping_.find(iter->id());
-    if (overscan_insets != overscan_mapping_.end()) {
-      gfx::Rect bounds = iter->bounds_in_pixel();
-      bounds.Inset(overscan_insets->second.Scale(iter->device_scale_factor()));
-      iter->SetScaleAndBounds(iter->device_scale_factor(), bounds);
-    }
+    if (overscan_insets != overscan_mapping_.end())
+      iter->SetOverscanInsets(overscan_insets->second);
   }
 
   std::sort(displays_.begin(), displays_.end(), DisplaySortFunctor());
   std::sort(new_displays.begin(), new_displays.end(), DisplaySortFunctor());
   DisplayList removed_displays;
   std::vector<size_t> changed_display_indices;
   std::vector<size_t> added_display_indices;
   gfx::Display current_primary;
   if (Shell::HasInstance())
     current_primary = Shell::GetScreen()->GetPrimaryDisplay();
@@ skipping 254 matching lines @@
   DisplayList::iterator iter_to_update = to_update->begin();
   DisplayList::const_iterator iter = displays_.begin();
   for (; iter != displays_.end() && iter_to_update != to_update->end();
        ++iter, ++iter_to_update) {
     (*iter_to_update).set_id((*iter).id());
   }
 }
 
 }  // namespace internal
 }  // namespace ash