Use GLX_SGI_video_sync to get a vblank signal.

content/common/gpu/image_transport_surface.cc

Index: content/common/gpu/image_transport_surface.cc
diff --git a/content/common/gpu/image_transport_surface.cc b/content/common/gpu/image_transport_surface.cc
index e0f1e2f0e68c665b7ef6e508e348fd3cdb66bd0b..d9ea02e64b879d05ef51f928be851fd28bddad01 100644
--- a/content/common/gpu/image_transport_surface.cc
+++ b/content/common/gpu/image_transport_surface.cc
@@ -353,11 +353,9 @@ gfx::Size PassThroughImageTransportSurface::GetSize() {
 PassThroughImageTransportSurface::~PassThroughImageTransportSurface() {}
 
 void PassThroughImageTransportSurface::SendVSyncUpdateIfAvailable() {
-  base::TimeTicks timebase;
-  base::TimeDelta interval;
-  if (GetVSyncParameters(&timebase, &interval)) {
-    helper_->SendUpdateVSyncParameters(timebase, interval);
-  }
+  GetVSyncParameters(
+      base::Bind(&ImageTransportHelper::SendUpdateVSyncParameters,
+                 helper_->AsWeakPtr()));
 }
 
 }  // namespace content