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

ui/aura/mus/window_tree_client.h

Index: ui/aura/mus/window_tree_client.h
diff --git a/ui/aura/mus/window_tree_client.h b/ui/aura/mus/window_tree_client.h
index 3e42a2ef2ad82ef9eee1425bc0a0396e3f2e31d9..ef5aacae082ceee3c8a3af4e4333d55122f51951 100644
--- a/ui/aura/mus/window_tree_client.h
+++ b/ui/aura/mus/window_tree_client.h
@@ -21,6 +21,7 @@
 #include "mojo/public/cpp/bindings/associated_binding.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
 #include "services/ui/public/interfaces/window_tree.mojom.h"
+#include "services/ui/public/interfaces/window_tree_host.mojom.h"
 #include "ui/aura/aura_export.h"
 #include "ui/aura/client/transient_window_client_observer.h"
 #include "ui/aura/mus/capture_synchronizer_delegate.h"
@@ -97,9 +98,17 @@ class AURA_EXPORT WindowTreeClient
   // Establishes the connection by way of the WindowTreeFactory.
   void ConnectViaWindowTreeFactory();
 
+  // Establishes the connection by way of the WindowTreeFactoryHost.
+  void ConnectViaWindowTreeHostFactory();
+
   // Establishes the connection by way of WindowManagerWindowTreeFactory.
   void ConnectAsWindowManager();
 
+  // Triggers the creation of a mojom::WindowTreeHost (aka ws::Display)
+  // instance on the server side.
+  // This ends up calling back to client side, ui::WindowtreeClient::OnEmbed.
+  void CreateHost(ui::mojom::WindowTreeHostRequest host);
+
   service_manager::Connector* connector() { return connector_; }
   ui::Gpu* gpu() { return gpu_.get(); }
   CaptureSynchronizer* capture_synchronizer() {
@@ -544,6 +553,9 @@ class AURA_EXPORT WindowTreeClient
   // If |compositor_context_factory_| is installed on Env, then this is the
   // ContextFactory that was set on Env originally.
   ui::ContextFactory* initial_context_factory_ = nullptr;
+
+  ui::mojom::WindowTreeHostFactoryPtr window_tree_host_factory_ptr_;
+
   base::WeakPtrFactory<WindowTreeClient> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowTreeClient);