Don't use GL_FRAMEBUFFER_SRGB unless available. Don't try to enable or disable GL_FRAMEBUFFER_SRGB unless extensions.sRGBWriteControl is true. For example if you try it with Mesa GLES2 you get a GL error. BUG=angleproject:1896 Change-Id: I5f5b4e8ea4f5a7c6913f27761a6e2dc88aacc78c Reviewed-on: https://chromium-review.googlesource.com/443824 Commit-Queue: Frank Henigman <fjhenigman@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>