Re-land^2 WebVR compositor bypass via BrowserMain context + mailbox

device/vr/test/fake_vr_device.cc

Index: device/vr/test/fake_vr_device.cc
diff --git a/device/vr/test/fake_vr_device.cc b/device/vr/test/fake_vr_device.cc
index c699905019dff22bee1b1b63e2c6d2f13e57e77e..1fc359c8954b16c9929ec2f77c05f38fcfd05ef4 100644
--- a/device/vr/test/fake_vr_device.cc
+++ b/device/vr/test/fake_vr_device.cc
@@ -72,11 +72,19 @@ void FakeVRDevice::ExitPresent() {
   OnExitPresent();
 }
 
-void FakeVRDevice::SubmitFrame(mojom::VRPosePtr pose) {}
+void FakeVRDevice::SubmitFrame(int16_t frame_index,
+                               const gpu::Mailbox& mailbox,
+                               const gpu::SyncToken& sync_token,
+                               mojom::VRSubmitFrameClientPtr submit_client) {
+  submit_client->OnSubmitFrameTransferred();
+  submit_client->OnSubmitFrameRendered();
+}
 
 void FakeVRDevice::UpdateLayerBounds(int16_t frame_index,
                                      mojom::VRLayerBoundsPtr leftBounds,
-                                     mojom::VRLayerBoundsPtr rightBounds) {}
+                                     mojom::VRLayerBoundsPtr rightBounds,
+                                     int16_t source_width,
+                                     int16_t source_height) {}
 
 void FakeVRDevice::GetVRVSyncProvider(mojom::VRVSyncProviderRequest request) {}