c++ / mojo changes for 'external window mode'

services/ui/ws/display.cc

Index: services/ui/ws/display.cc
diff --git a/services/ui/ws/display.cc b/services/ui/ws/display.cc
index b3981b86032061140d6c25279a890a940e863eab..e2d76095f96b673a79ae7095fa42b07400e532b7 100644
--- a/services/ui/ws/display.cc
+++ b/services/ui/ws/display.cc
@@ -213,7 +213,15 @@ void Display::InitWindowManagerDisplayRoots() {
     // id works.
     window_manager_display_root_map_[service_manager::mojom::kRootUserID] =
         display_root_ptr.get();
-    WindowTree* window_tree = binding_->CreateWindowTree(display_root->root());
+
+    DCHECK(window_server_->window_tree_host_factory());
+    WindowTree* window_tree =
+        window_server_->window_tree_host_factory()->window_tree();
+    window_tree->AddRoot(display_root->root());
+    window_tree->DoOnEmbed(nullptr /*mojom::WindowTreePtr*/,

[fwang, 2017/02/28 08:23:53]

Is commenting nullptr parameter something common in chromium style?

+                           display_root->root());
+
+    window_tree->ConfigureWindowManager();
     display_root->window_manager_state_ = window_tree->window_manager_state();
     window_tree->window_manager_state()->AddWindowManagerDisplayRoot(
         std::move(display_root_ptr));