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

services/native_viewport/platform_viewport_android.cc

Index: services/native_viewport/platform_viewport_android.cc
diff --git a/services/native_viewport/platform_viewport_android.cc b/services/native_viewport/platform_viewport_android.cc
index a19d5c0dea643194bc5df660e9c88d2776b0c9c7..4a6d2b173b682f8bb04c4ade828151c6c12b4a30 100644
--- a/services/native_viewport/platform_viewport_android.cc
+++ b/services/native_viewport/platform_viewport_android.cc
@@ -148,10 +148,7 @@ bool PlatformViewportAndroid::TouchEvent(JNIEnv* env,
 
 void PlatformViewportAndroid::Init(const gfx::Rect& bounds) {
   JNIEnv* env = base::android::AttachCurrentThread();
-  java_platform_viewport_android_ = JavaObjectWeakGlobalRef(
-      env,
-      Java_PlatformViewportAndroid_create(env, reinterpret_cast<jlong>(this))
-          .obj());
+  Java_PlatformViewportAndroid_createNativeWindow(env);
 }
 
 void PlatformViewportAndroid::Show() {
@@ -177,6 +174,14 @@ void PlatformViewportAndroid::SetBounds(const gfx::Rect& bounds) {
   NOTIMPLEMENTED();
 }
 
+bool PlatformViewportAndroid::NewNativeSurfaceAvailable() {
+  JNIEnv* env = base::android::AttachCurrentThread();
+  java_platform_viewport_android_ = JavaObjectWeakGlobalRef(
+      env, Java_PlatformViewportAndroid_create(
+               env, reinterpret_cast<jlong>(this)).obj());
+  return true;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // PlatformViewportAndroid, private:
 
@@ -190,8 +195,8 @@ void PlatformViewportAndroid::ReleaseWindow() {
 
 // static
 scoped_ptr<PlatformViewport> PlatformViewport::Create(Delegate* delegate) {
-  return scoped_ptr<PlatformViewport>(
-      new PlatformViewportAndroid(delegate)).Pass();
+  return scoped_ptr<PlatformViewport>(new PlatformViewportAndroid(delegate))
+      .Pass();
 }
 
 }  // namespace native_viewport