Encode frame number in pixel data for pose sync

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 787dc0cba70c83f04670e74725a79cc109eef8c9..459fdb34461c9898af401794713b47e9f8d03bb2 100644
--- a/device/vr/android/gvr/gvr_device.cc
+++ b/device/vr/android/gvr/gvr_device.cc
@@ -134,6 +134,9 @@ VRPosePtr GvrDevice::GetPose() {
 
   pose->timestamp = base::Time::Now().ToJsTime();
 
+  // Increment pose frame counter always, even if it's a faked pose.
+  pose->poseNum = ++pose_num_;
+
   pose->orientation = mojo::Array<float>::New(4);
 
   gvr::GvrApi* gvr_api = GetGvrApi();
@@ -176,6 +179,10 @@ VRPosePtr GvrDevice::GetPose() {
     pose->position[2] = decomposed_transform.translate[2];
   }
 
+  // Save the underlying GVR pose for use by rendering. It can't use a
+  // VRPosePtr since that's a different data type.
+  delegate_->SetGvrPoseForWebVr(head_mat, pose_num_);
+
   return pose;
 }