The spec says that the initial condition of a FenceSync object should be
GL_SYNC_GPU_COMMANDS_COMPLETE.  Make sure this is set in case the
condition is queried before the fence is set.

TEST=conformance2/state/gl-object-get-calls.html
BUG=602688

Change-Id: I8c0451fc996c175109541f337191cc1be4b813e3
Reviewed-on: https://chromium-review.googlesource.com/457452Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Geoff Lang <geofflang@chromium.org>