Gets mustash frames looking like that of ash

mash/wm/non_client_frame_controller.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 MASH_WM_NON_CLIENT_FRAME_CONTROLLER_H_
 #define MASH_WM_NON_CLIENT_FRAME_CONTROLLER_H_
 
 #include "base/macros.h"
 #include "components/mus/public/cpp/window_observer.h"
 #include "ui/views/widget/widget_delegate.h"
 
+namespace gfx {
+class Insets;
+}
+
 namespace mojo {
 class Shell;
 }
 
 namespace mus {
 class Window;
 }
 
 // Provides the non-client frame for mus Windows.
 class NonClientFrameController : public views::WidgetDelegateView,
                                  public mus::WindowObserver {
  public:
   // NonClientFrameController deletes itself when |window| is destroyed.
   NonClientFrameController(mojo::Shell* shell, mus::Window* window);
 
+  // Returns the preferred client area insets.
+  static gfx::Insets GetPreferredClientAreaInsets();
+
  private:
   ~NonClientFrameController() override;
 
   // views::WidgetDelegateView:
   views::View* GetContentsView() override;
   bool CanResize() const override;
   bool CanMaximize() const override;
   bool CanMinimize() const override;
 
   // mus::WindowObserver:
   void OnWindowSharedPropertyChanged(
       mus::Window* window,
       const std::string& name,
       const std::vector<uint8_t>* old_data,
       const std::vector<uint8_t>* new_data) override;
   void OnWindowDestroyed(mus::Window* window) override;
 
   views::Widget* widget_;
 
   // WARNING: as widget delays destruction there is a portion of time when this
   // is null.
   mus::Window* window_;
 
   DISALLOW_COPY_AND_ASSIGN(NonClientFrameController);
 };
 
 #endif  // MASH_WM_NON_CLIENT_FRAME_CONTROLLER_H_