This replaces the dlsyming of glX entry point with linking to libGL
which in trun allows the ANGLE to be traced using apitrace.

Re-land with a trivial compilation fix (MEMBER vs MEMEBER)

BUG=angleproject:892

Change-Id: Ie89b6fe26eb80d3d8d48f49645d7a6254230bf5c
Reviewed-on: https://chromium-review.googlesource.com/287143Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tested-by: Corentin Wallez <cwallez@chromium.org>