WebVR: add angular velocity estimate to pose

chrome/browser/android/vr_shell/non_presenting_gvr_delegate.cc

Index: chrome/browser/android/vr_shell/non_presenting_gvr_delegate.cc
diff --git a/chrome/browser/android/vr_shell/non_presenting_gvr_delegate.cc b/chrome/browser/android/vr_shell/non_presenting_gvr_delegate.cc
index c2457ba4176e627bc8351dec29fdc59ff6924d6c..8ae932a349273b6b1051c1f81b984ca60e9e92b3 100644
--- a/chrome/browser/android/vr_shell/non_presenting_gvr_delegate.cc
+++ b/chrome/browser/android/vr_shell/non_presenting_gvr_delegate.cc
@@ -13,7 +13,9 @@
 namespace vr_shell {
 
 namespace {
+// TODO(klausw): These are duplicates from vr_shell_gl.cc, put in header file?

[billorr, 2017/03/27 17:33:53]

any reason not to do this now?

[klausw, 2017/03/27 17:55:42]

Done - though it's annoying that it's now no longer possible to fit a simple "a
+= b" on a single line due to the added "VrShell::" prefix.

 static constexpr int64_t kPredictionTimeWithoutVsyncNanos = 50000000;
+static constexpr int64_t kAngularVelocityEpsilonNanos = 1000000;
 }  // namespace
 
 NonPresentingGvrDelegate::NonPresentingGvrDelegate(gvr_context* context)
@@ -153,8 +155,14 @@ void NonPresentingGvrDelegate::SendVSync(base::TimeDelta time,
 
   gvr::Mat4f head_mat = gvr_api_->ApplyNeckModel(
       gvr_api_->GetHeadSpaceFromStartSpaceRotation(target_time), 1.0f);
-  callback.Run(VrShell::VRPosePtrFromGvrPose(head_mat), time, -1,
-               device::mojom::VRVSyncProvider::Status::SUCCESS);
+
+  target_time.monotonic_system_time_nanos += kAngularVelocityEpsilonNanos;
+  gvr::Mat4f head_mat_2 =
+      gvr_api_->GetHeadSpaceFromStartSpaceRotation(target_time);
+
+  callback.Run(VrShell::VRPosePtrFromGvrPose(head_mat, head_mat_2,
+                                             kAngularVelocityEpsilonNanos),
+               time, -1, device::mojom::VRVSyncProvider::Status::SUCCESS);
 }
 
 bool NonPresentingGvrDelegate::SupportsPresentation() {