VR: Fix spinner for slow WebXR rendering

Bug: 881970
Change-Id: I23d7c563929d0c95459050669b3303eba3785128
Reviewed-on: https://chromium-review.googlesource.com/1216464Reviewed-by: Michael Thiessen <mthiesse@chromium.org>
Commit-Queue: Aldo Culquicondor <acondor@chromium.org>
Cr-Commit-Position: refs/heads/master@{#589930}

chrome/browser/android/vr/gvr_scheduler_delegate.cc

@@ -208,8 +208,6 @@ void GvrSchedulerDelegate::ConnectPresentingService(
     CreateOrResizeWebXrSurface(webxr_size);
   }
 
-  ScheduleOrCancelWebVrFrameTimeout();
-
   auto submit_frame_sink = device::mojom::XRPresentationConnection::New();
   submit_frame_sink->client_request = mojo::MakeRequest(&submit_client_);
   submit_frame_sink->provider = presentation_provider.PassInterface();
@@ -220,6 +218,8 @@ void GvrSchedulerDelegate::ConnectPresentingService(
   session->submit_frame_sink = std::move(submit_frame_sink);
   session->display_info = std::move(display_info);
 
+  ScheduleOrCancelWebVrFrameTimeout();
+
   browser_->SendRequestPresentReply(std::move(session));
 }