mus: Changes SetDisplayRoot() to create actual display

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 <vector>
 
 #include "base/memory/ptr_util.h"
 #include "base/trace_event/trace_event.h"
@@ skipping 59 matching lines @@
         base::MakeUnique<CursorLocationManager>();
   }
   return cursor_location_managers_[user_id].get();
 }
 
 void DisplayManager::AddDisplay(Display* display) {
   DCHECK_EQ(0u, pending_displays_.count(display));
   pending_displays_.insert(display);
 }
 
+void DisplayManager::AddDisplayForWindowManager(
+    const display::Display& display,
+    const display::ViewportMetrics& metrics) {
+  OnDisplayAdded(display, metrics);
+}
+
 void DisplayManager::DestroyDisplay(Display* display) {
   if (pending_displays_.count(display)) {
     pending_displays_.erase(display);
   } else {
     for (const auto& pair : user_display_managers_)
       pair.second->OnWillDestroyDisplay(display->GetId());
 
     DCHECK(displays_.count(display));
     displays_.erase(display);
     window_server_->OnDisplayDestroyed(display);
@@ skipping 159 matching lines @@
   DVLOG(3) << "OnPrimaryDisplayChanged: " << 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