video_decode_accelerator_unittest: enable test on ozone surfaceless

ui/ozone/platform/dri/gbm_surfaceless.cc

Index: ui/ozone/platform/dri/gbm_surfaceless.cc
diff --git a/ui/ozone/platform/dri/gbm_surfaceless.cc b/ui/ozone/platform/dri/gbm_surfaceless.cc
index efa09797c57a68a777ad796735d07ca71e30b0ce..308fb9ba936315af70e41227a9a5ed5736118d73 100644
--- a/ui/ozone/platform/dri/gbm_surfaceless.cc
+++ b/ui/ozone/platform/dri/gbm_surfaceless.cc
@@ -27,8 +27,11 @@ bool GbmSurfaceless::ResizeNativeWindow(const gfx::Size& viewport_size) {
 }
 
 bool GbmSurfaceless::OnSwapBuffers() {
-  NOTREACHED();
-  return false;
+  HardwareDisplayController* controller = window_delegate_->GetController();
+  if (!controller)
+    return true;
+
+  return controller->PageFlip();
 }
 
 bool GbmSurfaceless::OnSwapBuffersAsync(