Fix root ServerWindow size.

services/ui/ws/display_manager.cc

 // Copyright 2016 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 "services/ui/ws/display_manager.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/trace_event/trace_event.h"
 #include "services/ui/display/platform_screen.h"
 #include "services/ui/ws/display.h"
@@ skipping 191 matching lines @@
     return;
 
   // Send IPCs to WM clients first with new display information.
   std::vector<WindowManagerWindowTreeFactory*> factories =
       window_server_->window_manager_window_tree_factory_set()->GetFactories();
   for (WindowManagerWindowTreeFactory* factory : factories) {
     if (factory->window_tree())
       factory->window_tree()->OnWmDisplayModified(display->ToDisplay());
   }
 
+  // Change the root ServerWindow size after sending IPC to WM.
   display->OnViewportMetricsChanged(metrics);
   OnDisplayUpdate(display);
 }
 
 void DisplayManager::OnPrimaryDisplayChanged(int64_t primary_display_id) {
   // TODO(kylechar): Send IPCs to WM clients first.
 
   // Send IPCs to any DisplayManagerObservers.
   for (const auto& pair : user_display_managers_)
     pair.second->OnPrimaryDisplayChanged(primary_display_id);
 }
 
 }  // namespace ws
 }  // namespace ui