Move the GL_APICALL and similar defines to the project level.

BUG=angle:658

Change-Id: Ib4fa10bb89a6658efbc20d5a763d8ec9c3a5506f
Reviewed-on: https://chromium-review.googlesource.com/201465
Tested-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
21 files changed