Extract shell methods from ApplicationImpl into a base class, and pass this to Initialize() instead.

ui/views/mus/platform_window_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/platform_window_mus.h"
 
 #include "build/build_config.h"
 #include "components/bitmap_uploader/bitmap_uploader.h"
 #include "components/mus/public/cpp/property_type_converters.h"
 #include "components/mus/public/cpp/window_property.h"
 #include "components/mus/public/interfaces/window_manager.mojom.h"
 #include "mojo/converters/input_events/input_events_type_converters.h"
 #include "ui/base/view_prop.h"
 #include "ui/platform_window/platform_window_delegate.h"
 #include "ui/views/mus/window_manager_connection.h"
 
 namespace views {
 
 namespace {
 static uint32_t accelerated_widget_count = 1;
 
 }  // namespace
 
 PlatformWindowMus::PlatformWindowMus(ui::PlatformWindowDelegate* delegate,
-                                     mojo::shell::mojom::Shell* shell,
+                                     mojo::Shell* shell,
                                      mus::Window* mus_window)
     : delegate_(delegate),
       mus_window_(mus_window),
       show_state_(mus::mojom::ShowState::RESTORED),
       last_cursor_(mus::mojom::Cursor::CURSOR_NULL),
       has_capture_(false),
       mus_window_destroyed_(false) {
   DCHECK(delegate_);
   DCHECK(mus_window_);
   mus_window_->AddObserver(this);
@@ skipping 196 matching lines @@
   // It's possible dispatching the event will spin a nested message loop. Ack
   // the callback now, otherwise we appear unresponsive for the life of the
   // nested message loop.
   (*ack_callback)->Run();
   ack_callback->reset();
   scoped_ptr<ui::Event> ui_event(event.To<scoped_ptr<ui::Event>>());
   delegate_->DispatchEvent(ui_event.get());
 }
 
 }  // namespace views