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

device/vr/android/gvr/gvr_delegate.h

Index: device/vr/android/gvr/gvr_delegate.h
diff --git a/device/vr/android/gvr/gvr_delegate.h b/device/vr/android/gvr/gvr_delegate.h
index 3c61aa1e37fdde9f52c9ca812c1f9008825139f4..e1db045a84d749f3b9502026a0db50a76272222d 100644
--- a/device/vr/android/gvr/gvr_delegate.h
+++ b/device/vr/android/gvr/gvr_delegate.h
@@ -10,6 +10,10 @@
 #include "device/vr/vr_service.mojom.h"
 #include "third_party/gvr-android-sdk/src/libraries/headers/vr/gvr/capi/include/gvr_types.h"
 
+namespace gpu {
+class Mailbox;
+}
+
 namespace device {
 
 constexpr gvr::Sizei kInvalidRenderTargetSize = {0, 0};
@@ -17,7 +21,7 @@ constexpr gvr::Sizei kInvalidRenderTargetSize = {0, 0};
 class DEVICE_VR_EXPORT GvrDelegate {
  public:
   virtual void SetWebVRSecureOrigin(bool secure_origin) = 0;
-  virtual void SubmitWebVRFrame() = 0;
+  virtual void SubmitWebVRFrame(int frame_index, const gpu::Mailbox&) = 0;
   virtual void UpdateWebVRTextureBounds(int16_t frame_index,
                                         const gvr::Rectf& left_bounds,
                                         const gvr::Rectf& right_bounds) = 0;