Revert of Add a basic browser to mash that uses the navigation service.

ui/views/mus/native_widget_mus.cc

 // Copyright 2015 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 "ui/views/mus/native_widget_mus.h"
 
 #include "base/macros.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "components/mus/public/cpp/property_type_converters.h"
 #include "components/mus/public/cpp/window.h"
@@ skipping 454 matching lines @@
 aura::Window* NativeWidgetMus::GetRootWindow() {
   return window_tree_host_->window();
 }
 
 void NativeWidgetMus::OnPlatformWindowClosed() {
   native_widget_delegate_->OnNativeWidgetDestroying();
 
   window_tree_client_.reset();  // Uses |content_|.
   capture_client_.reset();      // Uses |content_|.
 
+  cursor_manager_.reset();      // Uses |window_|.
+
   window_tree_host_->RemoveObserver(this);
   window_tree_host_.reset();
 
-  cursor_manager_.reset();  // Uses |window_|.
-
   mus_window_observer_.reset(nullptr);
 
   window_ = nullptr;
   content_ = nullptr;
 
   native_widget_delegate_->OnNativeWidgetDestroyed();
   if (ownership_ == Widget::InitParams::NATIVE_WIDGET_OWNS_WIDGET)
     delete this;
 }
 
@@ skipping 733 matching lines @@
     GetNativeWindow()->Show();
   } else {
     window_tree_host_->Hide();
     window_->SetVisible(false);
     GetNativeWindow()->Hide();
   }
   native_widget_delegate_->OnNativeWidgetVisibilityChanged(window->visible());
 }
 
 }  // namespace views