Undo all existing overscan settings before updating to a new overscan settings (2nd)

ash/display/display_controller.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/display_controller.h"
 
 #include <algorithm>
 
 #include "ash/ash_switches.h"
 #include "ash/display/display_manager.h"
@@ skipping 431 matching lines @@
   // Update the layout.
   SetLayoutForDisplayName(
       display_manager->GetDisplayNameFor(old_primary_display),
       GetLayoutForDisplay(new_primary_display).Invert());
 
   // Update the dispay manager with new display info.
   std::vector<gfx::Display> displays;
   displays.push_back(display_manager->GetDisplayForId(primary_display_id));
   displays.push_back(*GetSecondaryDisplay());
   GetDisplayManager()->set_force_bounds_changed(true);
-  GetDisplayManager()->OnNativeDisplaysChanged(displays);
+  GetDisplayManager()->UpdateDisplays(displays);
   GetDisplayManager()->set_force_bounds_changed(false);
 }
 
 gfx::Display* DisplayController::GetSecondaryDisplay() {
   internal::DisplayManager* display_manager = GetDisplayManager();
   CHECK_EQ(2U, display_manager->GetNumDisplays());
   return display_manager->GetDisplayAt(0)->id() == primary_display_id ?
       display_manager->GetDisplayAt(1) : display_manager->GetDisplayAt(0);
 }
 
@@ skipping 113 matching lines @@
   secondary_display->set_bounds(
       gfx::Rect(new_secondary_origin, secondary_bounds.size()));
   secondary_display->UpdateWorkAreaFromInsets(insets);
 }
 
 void DisplayController::NotifyDisplayConfigurationChanging() {
   FOR_EACH_OBSERVER(Observer, observers_, OnDisplayConfigurationChanging());
 }
 
 }  // namespace ash