Gets chrome --mus some what working

ui/aura/mus/window_tree_client.cc

 // 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.
 
 #include "ui/aura/mus/window_tree_client.h"
 
 #include <stddef.h>
 
 #include <string>
 #include <utility>
@@ skipping 535 matching lines @@
   delegate_->OnEmbed(std::move(window_tree_host));
 }
 
 WindowTreeHostMus* WindowTreeClient::WmNewDisplayAddedImpl(
     const display::Display& display,
     ui::mojom::WindowDataPtr root_data,
     bool parent_drawn,
     const cc::FrameSinkId& frame_sink_id) {
   DCHECK(window_manager_delegate_);
 
+  got_initial_displays_ = true;
+
   window_manager_delegate_->OnWmWillCreateDisplay(display);
 
   std::unique_ptr<WindowTreeHostMus> window_tree_host = CreateWindowTreeHost(
       WindowMusType::DISPLAY, *root_data, display.id(), frame_sink_id);
 
   WindowTreeHostMus* window_tree_host_ptr = window_tree_host.get();
   window_manager_delegate_->OnWmNewDisplay(std::move(window_tree_host),
                                            display);
   return window_tree_host_ptr;
 }
@@ skipping 793 matching lines @@
 void WindowTreeClient::RequestClose(uint32_t window_id) {
   WindowMus* window = GetWindowByServerId(window_id);
   if (!window || !IsRoot(window))
     return;
 
   // Since the window is the root window, we send close request to the entire
   // WindowTreeHost.
   GetWindowTreeHostMus(window->GetWindow())->OnCloseRequest();
 }
 
+bool WindowTreeClient::WaitForInitialDisplays() {
+  if (got_initial_displays_)
+    return true;
+
+  bool valid_wait = true;
+  // TODO(sky): having to block here is not ideal. http://crbug.com/594852.
+  while (!got_initial_displays_ && valid_wait)
+    valid_wait = binding_.WaitForIncomingMethodCall();
+  return valid_wait;
+}
+
 void WindowTreeClient::OnConnect(ClientSpecificId client_id) {
   client_id_ = client_id;
 }
 
 void WindowTreeClient::WmNewDisplayAdded(const display::Display& display,
                                          ui::mojom::WindowDataPtr root_data,
                                          bool parent_drawn,
                                          const cc::FrameSinkId& frame_sink_id) {
   WmNewDisplayAddedImpl(display, std::move(root_data), parent_drawn,
                         frame_sink_id);
@@ skipping 536 matching lines @@
   return ScheduleInFlightChange(base::MakeUnique<InFlightCaptureChange>(
       this, capture_synchronizer_.get(), window));
 }
 
 uint32_t WindowTreeClient::CreateChangeIdForFocus(WindowMus* window) {
   return ScheduleInFlightChange(base::MakeUnique<InFlightFocusChange>(
       this, focus_synchronizer_.get(), window));
 }
 
 }  // namespace aura