Allow native_viewport to create new native windows on demand on Android.

shell/android/main.cc

Index: shell/android/main.cc
diff --git a/shell/android/main.cc b/shell/android/main.cc
index 6502015c0b28692fdc5dbc9b8be0dbaf10592d93..76cd4a56e5a4bc3407e8ecbf5f6d763970e87e1a 100644
--- a/shell/android/main.cc
+++ b/shell/android/main.cc
@@ -23,6 +23,7 @@
 #include "base/threading/simple_thread.h"
 #include "jni/ShellService_jni.h"
 #include "mojo/common/message_pump_mojo.h"
+#include "mojo/services/native_viewport/public/interfaces/native_viewport.mojom.h"
 #include "mojo/services/network/public/interfaces/network_service.mojom.h"
 #include "mojo/services/window_manager/public/interfaces/window_manager.mojom.h"
 #include "shell/android/android_handler_loader.h"
@@ -92,6 +93,7 @@ struct InternalShellData {
 
   // Proxy to a Window Manager, initialized on the shell thread.
   mojo::WindowManagerPtr window_manager;
+  mojo::NativeViewportShellServicePtr native_viewport;
 
   // TaskRunner used to execute tasks on the shell thread.
   scoped_refptr<base::SingleThreadTaskRunner> shell_task_runner;
@@ -196,6 +198,16 @@ void ConnectToApplicationImpl(
       url, GURL(), services.Pass(), exposed_services.Pass(), base::Closure());
 }
 
+void SendSurfaceAvailable() {
+  if (!g_internal_data.Get().native_viewport.get()) {
+    Context* context = g_internal_data.Get().context.get();
+    context->application_manager()->ConnectToService(
+        GURL("mojo:native_viewport_service"),
+        &g_internal_data.Get().native_viewport);
+  }
+  g_internal_data.Get().native_viewport->NewNativeSurfaceAvailable();
+}
+
 void EmbedApplicationByURL(std::string url) {
   DCHECK(g_internal_data.Get().shell_task_runner->RunsTasksOnCurrentThread());
   if (!g_internal_data.Get().window_manager.get()) {
@@ -335,6 +347,11 @@ static void ConnectToApplication(JNIEnv* env,
                      mojo::MessagePipeHandle(exposed_services_handle)))));
 }
 
+static void SurfaceAvailable(JNIEnv* env, jclass clazz) {
+  g_internal_data.Get().shell_task_runner->PostTask(
+      FROM_HERE, base::Bind(&SendSurfaceAvailable));
+}
+
 bool RegisterShellService(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }