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

services/native_viewport/platform_viewport_headless.cc

Index: services/native_viewport/platform_viewport_headless.cc
diff --git a/services/native_viewport/platform_viewport_headless.cc b/services/native_viewport/platform_viewport_headless.cc
index 1f77ba1c82b8a7311606dc7ef0472f7ddad31359..05bce0423199703cee9505ece147861db5afff1f 100644
--- a/services/native_viewport/platform_viewport_headless.cc
+++ b/services/native_viewport/platform_viewport_headless.cc
@@ -9,22 +9,18 @@
 namespace native_viewport {
 
 PlatformViewportHeadless::PlatformViewportHeadless(Delegate* delegate)
-    : delegate_(delegate) {
-}
+    : delegate_(delegate) {}
 
-PlatformViewportHeadless::~PlatformViewportHeadless() {
-}
+PlatformViewportHeadless::~PlatformViewportHeadless() {}
 
 void PlatformViewportHeadless::Init(const gfx::Rect& bounds) {
   metrics_ = mojo::ViewportMetrics::New();
   metrics_->size = mojo::Size::From(bounds.size());
 }
 
-void PlatformViewportHeadless::Show() {
-}
+void PlatformViewportHeadless::Show() {}
 
-void PlatformViewportHeadless::Hide() {
-}
+void PlatformViewportHeadless::Hide() {}
 
 void PlatformViewportHeadless::Close() {
   delegate_->OnDestroyed();
@@ -39,11 +35,16 @@ void PlatformViewportHeadless::SetBounds(const gfx::Rect& bounds) {
   delegate_->OnMetricsChanged(metrics_->Clone());
 }
 
+bool PlatformViewportHeadless::NewNativeSurfaceAvailable() {
+  NOTREACHED() << "Cannot attach a headless viewport to a native surface.";
+  return false;
+}
+
 // static
 scoped_ptr<PlatformViewport> PlatformViewportHeadless::Create(
     Delegate* delegate) {
-  return scoped_ptr<PlatformViewport>(
-      new PlatformViewportHeadless(delegate)).Pass();
+  return scoped_ptr<PlatformViewport>(new PlatformViewportHeadless(delegate))
+      .Pass();
 }
 
 }  // namespace native_viewport