glretrace: Fixed issue where state could be dumped before the requested call had been executed in a multithreaded trace.

For example when getting state for a particular Draw call, the
framebuffer could contain the contents prior to the Draw call.

Change-Id: I16e404f78dde37cf3fe521d14d491ca6de78e327
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/apitrace/+/2224542
Reviewed-by: Po-Hsien Wang <pwang@chromium.org>
Commit-Queue: Robert Tarasov <tutankhamen@chromium.org>
Tested-by: Robert Tarasov <tutankhamen@chromium.org>
1 file changed