Mojo-ify implementation of screen orientation locking/unlocking.

content/browser/frame_host/render_frame_host_delegate.cc

Index: content/browser/frame_host/render_frame_host_delegate.cc
diff --git a/content/browser/frame_host/render_frame_host_delegate.cc b/content/browser/frame_host/render_frame_host_delegate.cc
index c42d24a375b9d3b29691c572e14cbb871ac19dc0..efdafbb159d2f41ca62f24c1584fae2195c848e6 100644
--- a/content/browser/frame_host/render_frame_host_delegate.cc
+++ b/content/browser/frame_host/render_frame_host_delegate.cc
@@ -77,6 +77,10 @@ RenderFrameHostDelegate::GetWakeLockServiceContext() {
   return nullptr;
 }
 
+ScreenOrientationImpl* RenderFrameHostDelegate::GetScreenOrientation() {
+  return nullptr;
+}
+
 bool RenderFrameHostDelegate::ShouldRouteMessageEvent(
     RenderFrameHost* target_rfh,
     SiteInstance* source_site_instance) const {