Fixes bug where client area would not get set correctly

ui/views/mus/native_widget_mus.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_NATIVE_WIDGET_MUS_H_
 #define UI_VIEWS_MUS_NATIVE_WIDGET_MUS_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 66 matching lines @@
   void OnPlatformWindowClosed();
   void OnActivationChanged(bool active);
 
  protected:
   // Updates the client area in the mus::Window.
   virtual void UpdateClientArea();
 
   // internal::NativeWidgetPrivate:
   NonClientFrameView* CreateNonClientFrameView() override;
   void InitNativeWidget(const Widget::InitParams& params) override;
+  void OnWidgetInitDone() override;
   bool ShouldUseNativeFrame() const override;
   bool ShouldWindowContentsBeTransparent() const override;
   void FrameTypeChanged() override;
   Widget* GetWidget() override;
   const Widget* GetWidget() const override;
   gfx::NativeView GetNativeView() const override;
   gfx::NativeWindow GetNativeWindow() const override;
   Widget* GetTopLevelWidget() override;
   const ui::Compositor* GetCompositor() const override;
   const ui::Layer* GetLayer() const override;
@@ skipping 120 matching lines @@
   scoped_ptr<aura::client::DefaultCaptureClient> capture_client_;
   scoped_ptr<aura::client::WindowTreeClient> window_tree_client_;
   base::WeakPtrFactory<NativeWidgetMus> close_widget_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeWidgetMus);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_MUS_NATIVE_WIDGET_MUS_H_