Avoid redundant INSERT_PROC_ADDRESS calls PVS-Studio pointed out that seven GL functions were being initialized twice. This isn't critical but is slightly inefficient. R=jmadill@chromium.org BUG=697659 Change-Id: I199bd06ae1136bc3b8efd519787d89f4447f326d Reviewed-on: https://chromium-review.googlesource.com/448639 Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org>