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

services/ui/ws/window_tree.cc

Index: services/ui/ws/window_tree.cc
diff --git a/services/ui/ws/window_tree.cc b/services/ui/ws/window_tree.cc
index f642e1f1c3291f98d25ebcc946bb1336a56e9068..f227b6cbcdaca550b06a74b05f4aa8cf1213d363 100644
--- a/services/ui/ws/window_tree.cc
+++ b/services/ui/ws/window_tree.cc
@@ -100,9 +100,20 @@ void WindowTree::Init(std::unique_ptr<WindowTreeBinding> binding,
   if (roots_.empty())
     return;
 
+  DoOnEmbed(std::move(tree), nullptr /*ServerWindow*/);
+}
+
+void WindowTree::DoOnEmbed(mojom::WindowTreePtr tree,
+                           ServerWindow* root_window) {
   std::vector<const ServerWindow*> to_send;
-  CHECK_EQ(1u, roots_.size());
-  const ServerWindow* root = *roots_.begin();
+
+  bool in_external_window_mode = !!root_window;
+  if (in_external_window_mode)
+    CHECK_LE(1u, roots_.size());
+  else
+    CHECK_EQ(1u, roots_.size());

[fwang, 2017/03/01 06:38:47]

Does that compile when assertions are disabled?

+
+  const ServerWindow* root = root_window ? root_window : *roots_.begin();
   GetUnknownWindowsFrom(root, &to_send);
 
   Display* display = GetDisplay(root);
@@ -189,8 +200,7 @@ void WindowTree::PrepareForWindowServerShutdown() {
     window_manager_internal_ = binding_->GetWindowManager();
 }
 
-void WindowTree::AddRootForWindowManager(const ServerWindow* root) {
-  DCHECK(window_manager_internal_);
+void WindowTree::AddRoot(const ServerWindow* root) {
   const ClientWindowId client_window_id(WindowIdToTransportId(root->id()));
   DCHECK_EQ(0u, client_id_to_window_id_map_.count(client_window_id));
   client_id_to_window_id_map_[client_window_id] = root->id();
@@ -199,8 +209,12 @@ void WindowTree::AddRootForWindowManager(const ServerWindow* root) {
 
   Display* display = GetDisplay(root);
   DCHECK(display);
+}
 
-  window_manager_internal_->WmNewDisplayAdded(display->ToDisplay(),
+void WindowTree::AddRootForWindowManager(const ServerWindow* root) {
+  DCHECK(window_manager_internal_);
+  AddRoot(root);
+  window_manager_internal_->WmNewDisplayAdded(GetDisplay(root)->ToDisplay(),
                                               WindowToWindowData(root),
                                               root->parent()->IsDrawn());
 }