Gets chrome --mus some what working

ui/aura/mus/window_tree_client.h

 // Copyright 2014 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_AURA_MUS_WINDOW_TREE_CLIENT_H_
 #define UI_AURA_MUS_WINDOW_TREE_CLIENT_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 438 matching lines @@
       ui::mojom::FrameDecorationValuesPtr values) override;
   void SetNonClientCursor(Window* window, ui::mojom::Cursor cursor_id) override;
   void AddAccelerators(std::vector<ui::mojom::WmAcceleratorPtr> accelerators,
                        const base::Callback<void(bool)>& callback) override;
   void RemoveAccelerator(uint32_t id) override;
   void AddActivationParent(Window* window) override;
   void RemoveActivationParent(Window* window) override;
   void ActivateNextWindow() override;
   void SetExtendedHitArea(Window* window, const gfx::Insets& hit_area) override;
   void RequestClose(Window* window) override;
+  bool WaitForInitialDisplays() override;
 
   // Overriden from WindowTreeHostMusDelegate:
   void OnWindowTreeHostBoundsWillChange(WindowTreeHostMus* window_tree_host,
                                         const gfx::Rect& bounds) override;
   void OnWindowTreeHostClientAreaWillChange(
       WindowTreeHostMus* window_tree_host,
       const gfx::Insets& client_area,
       const std::vector<gfx::Rect>& additional_client_areas) override;
   void OnWindowTreeHostHitTestMaskWillChange(
       WindowTreeHostMus* window_tree_host,
@@ skipping 112 matching lines @@
 
   std::unique_ptr<ui::Gpu> gpu_;
   std::unique_ptr<MusContextFactory> compositor_context_factory_;
 
   std::unique_ptr<discardable_memory::ClientDiscardableSharedMemoryManager>
       discardable_shared_memory_manager_;
 
   // If |compositor_context_factory_| is installed on Env, then this is the
   // ContextFactory that was set on Env originally.
   ui::ContextFactory* initial_context_factory_ = nullptr;
+
+  // Set to true once OnWmDisplayAdded() is called.
+  bool got_initial_displays_ = false;
+
   base::WeakPtrFactory<WindowTreeClient> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowTreeClient);
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_MUS_WINDOW_TREE_CLIENT_H_