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This CL makes several changes:
* Creates Trace{WGL,GLX,EGL}Api when --enable-service-tracing is passed. They
  were previously never used.
* Moves creation of {Trace,Log}*Api to a lower level, so that
  --enable-gpu-service-{tracing,logging} works with tests, too.
* Avoids creating Log*Api when --enable-gpu-service-logging is not passed.
* Adds GlImplementationWrapper to remove some duplicated code.

R=kbr,rjkroege
BUG=None

Change-Id: Icddb2927ff43cb4b6481e5e2b62745bee2cf4445
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1951489
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Auto-Submit: Thomas Anderson <thomasanderson@chromium.org>
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Reviewed-by: Robert Kroeger <rjkroege@chromium.org>
Cr-Commit-Position: refs/heads/master@{#723161}