Use the sh namespace for shader variables. Since these types originate from the translator, use an appropriate namespace. Also rename some of the gl helper functions to be more specific to their functionality. BUG=angle:466 Change-Id: Idc29987b2053b3c40748dd46b581f3dbd8a6fd61 Reviewed-on: https://chromium-review.googlesource.com/204680 Tested-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Zhenyao Mo <zmo@chromium.org>