Refactor the GL surfaces and framebuffers to not hold renderer objects. BUG=angleproject:2464 Change-Id: I20aabeef3de6cf1fc13a29b6220e040aa83184d7 Reviewed-on: https://chromium-review.googlesource.com/1039986 Commit-Queue: Geoff Lang <geofflang@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Frank Henigman <fjhenigman@chromium.org>