TranslatorGLSL: collect variables when flattening pramga invariant all BUG=chromium:659472 Change-Id: Icfeada9f09fff5d28eb3f4fafb2c94d57598af1f Reviewed-on: https://chromium-review.googlesource.com/403849 Commit-Queue: Corentin Wallez <cwallez@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org>