Gets chrome --mus some what working

ui/aura/mus/window_manager_delegate.h

Index: ui/aura/mus/window_manager_delegate.h
diff --git a/ui/aura/mus/window_manager_delegate.h b/ui/aura/mus/window_manager_delegate.h
index e193d5f062e362d766b94000f5fc57e97bfa07d5..a3a0f823531b46b175db101ad6f47e5f7c2a1a10 100644
--- a/ui/aura/mus/window_manager_delegate.h
+++ b/ui/aura/mus/window_manager_delegate.h
@@ -63,6 +63,9 @@ class AURA_EXPORT WindowManagerClient {
   // this does nothing.
   virtual void RequestClose(Window* window) = 0;
 
+  // Blocks until the initial displays have been received.
+  virtual bool WaitForInitialDisplays() = 0;
+
  protected:
   virtual ~WindowManagerClient() {}
 };