Refactor EGLDeviceEXT to remove renderer dependency BUG=angleproject:1190 Change-Id: I38604de469c5f7efaf37bcebf20bc6425df35e62 Reviewed-on: https://chromium-review.googlesource.com/309512 Reviewed-by: Geoff Lang <geofflang@chromium.org> Tryjob-Request: Jamie Madill <jmadill@chromium.org> Tested-by: Austin Kinross <aukinros@microsoft.com>