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

services/ui/ws/window_tree_host_factory.cc

Index: services/ui/ws/window_tree_host_factory.cc
diff --git a/services/ui/ws/window_tree_host_factory.cc b/services/ui/ws/window_tree_host_factory.cc
index 1a2170b0a67144aeeaf31f6260afcce47ada1e00..f0c9075a0252d94024beab94b3080cd9e2cd5c19 100644
--- a/services/ui/ws/window_tree_host_factory.cc
+++ b/services/ui/ws/window_tree_host_factory.cc
@@ -4,9 +4,12 @@
 
 #include "services/ui/ws/window_tree_host_factory.h"
 
+#include "services/ui/ws/default_access_policy.h"
 #include "services/ui/ws/display.h"
 #include "services/ui/ws/display_binding.h"
 #include "services/ui/ws/window_server.h"
+#include "services/ui/ws/window_tree.h"
+#include "services/ui/ws/window_tree_binding.h"
 
 namespace ui {
 namespace ws {
@@ -22,18 +25,39 @@ WindowTreeHostFactory::WindowTreeHostFactory(WindowServer* window_server,
 
 WindowTreeHostFactory::~WindowTreeHostFactory() {}
 
-void WindowTreeHostFactory::AddBinding(
-    mojom::WindowTreeHostFactoryRequest request) {
+void WindowTreeHostFactory::Init(mojom::WindowTreeHostFactoryRequest request,
+                                 mojom::WindowTreeRequest tree_request,
+                                 mojom::WindowTreeClientPtr tree_client) {
   bindings_.AddBinding(this, std::move(request));
+
+  std::unique_ptr<ws::WindowTree> tree(
+      new ws::WindowTree(window_server_, user_id_, nullptr /*ServerWindow*/,
+                         base::WrapUnique(new DefaultAccessPolicy)));
+
+  std::unique_ptr<ws::DefaultWindowTreeBinding> tree_binding(
+      new ws::DefaultWindowTreeBinding(tree.get(), window_server_,
+                                       std::move(tree_request),
+                                       std::move(tree_client)));
+
+  tree_ = tree.get();
+
+  // Pass nullptr as mojom::WindowTreePtr (3rd parameter), because in external
+  // window mode, the WindowTreePtr is created on the aura/WindowTreeClient
+  // side.
+  //
+  // NOTE: This call to ::AddTree calls ::Init. However, it will not trigger a
+  // ::OnEmbed call because the WindowTree instance was created above passing
+  // 'nullptr' as the ServerWindow, hence there is no 'root' yet.
+  window_server_->AddTree(std::move(tree), std::move(tree_binding),
+                          nullptr /*mojom::WindowTreePtr*/);
 }
 
 void WindowTreeHostFactory::CreateWindowTreeHost(
-    mojom::WindowTreeHostRequest host,
-    mojom::WindowTreeClientPtr tree_client) {
+    mojom::WindowTreeHostRequest tree_host_request) {
   Display* display = new Display(window_server_);
   std::unique_ptr<DisplayBindingImpl> display_binding(
-      new DisplayBindingImpl(std::move(host), display, user_id_,
-                             std::move(tree_client), window_server_));
+      new DisplayBindingImpl(std::move(tree_host_request), display, user_id_,
+                             nullptr /* tree_client */, window_server_));
   display->Init(platform_display_init_params_, std::move(display_binding));
 }