Only send vrdisplayactivate events to focused frames

third_party/WebKit/Source/modules/vr/VRDisplay.h

Index: third_party/WebKit/Source/modules/vr/VRDisplay.h
diff --git a/third_party/WebKit/Source/modules/vr/VRDisplay.h b/third_party/WebKit/Source/modules/vr/VRDisplay.h
index f81dd2bf83180ac552076138c700fcda296bf06f..2f0d66a66fb2ef6511b8ea4d6e75901d30cf71e3 100644
--- a/third_party/WebKit/Source/modules/vr/VRDisplay.h
+++ b/third_party/WebKit/Source/modules/vr/VRDisplay.h
@@ -150,7 +150,11 @@ class VRDisplay final : public EventTargetWithInlineData,
   Member<VREyeParameters> m_eyeParametersLeft;
   Member<VREyeParameters> m_eyeParametersRight;
   device::mojom::blink::VRPosePtr m_framePose;
-  int16_t m_frameId = -1;
+
+  // This frame ID is vr-specific and is used to track when frames arrive at the
+  // VR compositor so that it knows which poses to use, when to apply bounds
+  // updates, etc.
+  int16_t m_vrFrameId = -1;
   VRLayer m_layer;
   double m_depthNear = 0.01;
   double m_depthFar = 10000.0;