Pass the Mozart ViewHost into Dart

Dart needs access to the ViewHost in order to create child views.

sky/engine/bindings/internals.dart

@@ -11,3 +11,4 @@ int takeServiceRegistry() native "takeServiceRegistry";
 int takeServicesProvidedByEmbedder() native "takeServicesProvidedByEmbedder";
 int takeServicesProvidedToEmbedder() native "takeServicesProvidedToEmbedder";
 int takeShellProxyHandle() native "takeShellProxyHandle";
+int takeViewHostHandle() native "takeViewHostHandle";

sky/services/engine/BUILD.gn

@@ -15,6 +15,7 @@ mojom("interfaces") {
     "//mojo/services/asset_bundle/interfaces",
     "//mojo/services/gfx/composition/interfaces",
     "//mojo/services/service_registry/interfaces",
+    "//mojo/services/ui/views/interfaces",
     "//sky/services/pointer:interfaces",
   ]
 }

sky/services/engine/sky_engine.mojom

@@ -9,6 +9,7 @@ import "mojo/public/interfaces/application/shell.mojom";
 import "mojo/services/asset_bundle/interfaces/asset_bundle.mojom";
 import "mojo/services/gfx/composition/interfaces/scheduling.mojom";
 import "mojo/services/service_registry/interfaces/service_registry.mojom";
+import "mojo/services/ui/views/interfaces/views.mojom";
 import "sky/services/engine/input_event.mojom";
 import "sky/services/pointer/pointer.mojom";
 
@@ -32,6 +33,7 @@ struct ServicesData {
   mojo.ServiceRegistry? service_registry;
   mojo.ServiceProvider? services_provided_by_embedder;
   mojo.ServiceProvider&? services_provided_to_embedder;
+  mojo.ui.ViewHost? view_host;
   mojo.gfx.composition.SceneScheduler? scene_scheduler;
 };
 

sky/shell/platform/mojo/view_impl.cc

@@ -17,14 +17,16 @@ ViewImpl::ViewImpl(ServicesDataPtr services,
     : binding_(this), url_(url), listener_binding_(this) {
   DCHECK(services);
 
+  mojo::ui::ViewHostPtr view_host;
+
   // Views
   mojo::ConnectToService(
       services->shell.get(), "mojo:view_manager_service", &view_manager_);
   mojo::ui::ViewPtr view;
   binding_.Bind(mojo::GetProxy(&view));
   view_manager_->RegisterView(
-      view.Pass(), mojo::GetProxy(&view_host_), url_, callback);
-  view_host_->GetServiceProvider(mojo::GetProxy(&view_service_provider_));
+      view.Pass(), mojo::GetProxy(&view_host), url_, callback);
+  view_host->GetServiceProvider(mojo::GetProxy(&view_service_provider_));
 
   // Input
   mojo::ConnectToService(view_service_provider_.get(), &input_connection_);
@@ -34,8 +36,9 @@ ViewImpl::ViewImpl(ServicesDataPtr services,
 
   // Compositing
   mojo::gfx::composition::ScenePtr scene;
-  view_host_->CreateScene(mojo::GetProxy(&scene));
+  view_host->CreateScene(mojo::GetProxy(&scene));
   scene->GetScheduler(mojo::GetProxy(&services->scene_scheduler));
+  services->view_host = view_host.Pass();
 
   // Engine
   shell_view_.reset(new ShellView(Shell::Shared()));

sky/shell/platform/mojo/view_impl.h

@@ -49,7 +49,6 @@ class ViewImpl : public mojo::ui::View,
   mojo::StrongBinding<mojo::ui::View> binding_;
   std::string url_;
   mojo::ui::ViewManagerPtr view_manager_;
-  mojo::ui::ViewHostPtr view_host_;
   mojo::ServiceProviderPtr view_service_provider_;
   mojo::ui::InputConnectionPtr input_connection_;
   mojo::Binding<mojo::ui::InputListener> listener_binding_;

sky/shell/ui/internals.cc

@@ -51,6 +51,11 @@ void TakeServicesProvidedToEmbedder(Dart_NativeArguments args) {
       args, GetInternals()->TakeServicesProvidedToEmbedder().value());
 }
 
+void TakeViewHostHandle(Dart_NativeArguments args) {
+  Dart_SetIntegerReturnValue(
+      args, GetInternals()->TakeViewHostHandle().value());
+}
+
 static DartLibraryNatives* g_natives;
 
 void EnsureNatives() {
@@ -63,6 +68,7 @@ void EnsureNatives() {
     {"takeServicesProvidedByEmbedder", TakeServicesProvidedByEmbedder, 0, true},
     {"takeServicesProvidedToEmbedder", TakeServicesProvidedToEmbedder, 0, true},
     {"takeShellProxyHandle", TakeShellProxyHandle, 0, true},
+    {"takeViewHostHandle", TakeViewHostHandle, 0, true},
   });
 }
 
@@ -136,5 +142,9 @@ mojo::Handle Internals::TakeServicesProvidedToEmbedder() {
   return services_provided_to_embedder_.PassMessagePipe().release();
 }
 
+mojo::Handle Internals::TakeViewHostHandle() {
+  return services_ ? services_->view_host.PassInterface().PassHandle().release() : mojo::Handle();
+}
+
 }  // namespace shell
 }  // namespace sky

sky/shell/ui/internals.h

@@ -35,6 +35,7 @@ class Internals
   mojo::Handle TakeServicesProvidedByEmbedder();
   mojo::Handle TakeServicesProvidedToEmbedder();
   mojo::Handle TakeRootBundleHandle();
+  mojo::Handle TakeViewHostHandle();
 
  private:
   explicit Internals(ServicesDataPtr services,