mash: remove more shell/shelf WmWindow usage.

ash/shell_port.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 "ash/shell_port.h"
 
 #include <utility>
 
 #include "ash/accelerators/accelerator_controller.h"
 #include "ash/public/cpp/shell_window_ids.h"
@@ skipping 52 matching lines @@
 
 void ShellPort::RemoveLockStateObserver(LockStateObserver* observer) {
   lock_state_observers_.RemoveObserver(observer);
 }
 
 ShellPort::ShellPort() {
   DCHECK(!instance_);
   instance_ = this;
 }
 
-RootWindowController* ShellPort::GetPrimaryRootWindowController() {
-  return GetPrimaryRootWindow()->GetRootWindowController();
-}
-
 bool ShellPort::IsForceMaximizeOnFirstRun() {
   return Shell::Get()->shell_delegate()->IsForceMaximizeOnFirstRun();
 }
 
 bool ShellPort::IsSystemModalWindowOpen() {
   if (simulate_modal_window_open_for_testing_)
     return true;
 
   // Traverse all system modal containers, and find its direct child window
   // with "SystemModal" setting, and visible.
@@ skipping 29 matching lines @@
     }
   }
   for (aura::Window* root_window : root_windows) {
     RootWindowController::ForWindow(root_window)
         ->GetSystemModalLayoutManager(removed)
         ->DestroyModalBackground();
   }
 }
 
 }  // namespace ash