Remove rx::ShaderSh and move the shared code to the GL. The GL layer can interact with the translator directly, to query all the active shader variables and call ShCompile. BUG=angleproject:1159 Change-Id: I334a9bef28f93cf85dd8cac0fb8542ac567cc3ec Reviewed-on: https://chromium-review.googlesource.com/299877 Reviewed-by: Geoff Lang <geofflang@chromium.org> Tryjob-Request: Jamie Madill <jmadill@chromium.org> Tested-by: Jamie Madill <jmadill@chromium.org>