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

ui/views/mus/surface_binding.h

 // 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.
 
 #ifndef UI_VIEWS_MUS_SURFACE_BINDING_H_
 #define UI_VIEWS_MUS_SURFACE_BINDING_H_
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "components/mus/public/interfaces/window_tree.mojom.h"
 #include "ui/views/mus/mus_export.h"
 
 namespace cc {
 class OutputSurface;
 }
 
 namespace mojo {
-namespace shell {
-namespace mojom {
 class Shell;
 }
-}
-}
 
 namespace mus {
 class Window;
 }
 
 namespace views {
 
 // SurfaceBinding is responsible for managing the connections necessary to
 // bind a Window to the surfaces service.
 // Internally SurfaceBinding manages one connection (and related structures) per
 // WindowTree. That is, all Windows from a particular WindowTree share the same
 // connection.
 class VIEWS_MUS_EXPORT SurfaceBinding {
  public:
-  SurfaceBinding(mojo::shell::mojom::Shell* shell,
+  SurfaceBinding(mojo::Shell* shell,
                  mus::Window* window,
                  mus::mojom::SurfaceType surface_type);
   ~SurfaceBinding();
 
   // Creates an OutputSurface that renders to the Window supplied to the
   // constructor.
   scoped_ptr<cc::OutputSurface> CreateOutputSurface();
 
  private:
   class PerConnectionState;
 
   mus::Window* window_;
   const mus::mojom::SurfaceType surface_type_;
   scoped_refptr<PerConnectionState> state_;
 
   DISALLOW_COPY_AND_ASSIGN(SurfaceBinding);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_MUS_SURFACE_BINDING_H_