[WIP] ScreenManager: Add an external window mode

services/ui/ws/window_server.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 "services/ui/ws/window_server.h"
 
 #include <set>
 #include <string>
 
 #include "base/logging.h"
@@ skipping 746 matching lines @@
     return;
   for (auto& pair : tree_map_) {
     pair.second->ProcessTransientWindowRemoved(window, transient_child,
                                                IsOperationSource(pair.first));
   }
 }
 
 void WindowServer::OnGpuServiceInitialized() {
   // TODO(kylechar): When gpu channel is removed, this can instead happen
   // earlier, after GpuHost::OnInitialized().
-  delegate_->StartDisplayInit();
+  bool window_manager_connected = false;

[rjkroege, 2017/01/23 21:19:43]

Are you sure that this does the right thing in INTERNAL mode on Gpu service
restart?

[fwang, 2017/01/24 17:11:51]

Good point. As I see this commit does not change the fact that StartDisplayInit
may be called multiple times when Gpu is re-inited. However, maybe you mean that
the value of window_manager_connected may change when Gpu is re-inited?

+  for (auto* factory : window_manager_window_tree_factory_set_.GetFactories()) {
+    if (factory->window_tree()) {
+      window_manager_connected = true;
+      break;
+    }
+  }
+  delegate_->StartDisplayInit(window_manager_connected);
 }
 
 void WindowServer::OnSurfaceCreated(const cc::SurfaceInfo& surface_info) {
   WindowId window_id(
       WindowIdFromTransportId(surface_info.id().frame_sink_id().client_id()));
   ServerWindow* window = GetWindow(window_id);
   // If the window doesn't have a parent then we have nothing to propagate.
   if (!window)
     return;
 
@@ skipping 30 matching lines @@
 void WindowServer::OnUserIdAdded(const UserId& id) {
   activity_monitor_map_[id] = base::MakeUnique<UserActivityMonitor>(nullptr);
 }
 
 void WindowServer::OnUserIdRemoved(const UserId& id) {
   activity_monitor_map_.erase(id);
 }
 
 }  // namespace ws
 }  // namespace ui