Isolate a presenting VR device from pages other than the one presenting.

device/vr/android/gvr/gvr_device.cc

Index: device/vr/android/gvr/gvr_device.cc
diff --git a/device/vr/android/gvr/gvr_device.cc b/device/vr/android/gvr/gvr_device.cc
index f3eebd59c73aa5acbea725c52c065e584428d15d..d00fc9424b327340d9b18c4b05952c8666dd178d 100644
--- a/device/vr/android/gvr/gvr_device.cc
+++ b/device/vr/android/gvr/gvr_device.cc
@@ -141,15 +141,16 @@ void GvrDevice::ResetPose() {
   delegate_->gvr_api()->ResetTracking();
 }
 
-void GvrDevice::RequestPresent() {
+bool GvrDevice::RequestPresent() {
   delegate_->RequestWebVRPresent();
+  return true;
 }
 
 void GvrDevice::ExitPresent() {
   delegate_->ExitWebVRPresent();
 }
 
-void GvrDevice::SubmitFrame() {
+void GvrDevice::SubmitFrame(VRPosePtr pose) {
   delegate_->SubmitWebVRFrame();
 }