Use PathID in place of GLuint handle Bug: angleproject:3804 Change-Id: Ibadfc2c33e4af1cca22caa1dbe96ac48a4a85ffa Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1766822 Reviewed-by: Jiacheng Lu <lujc@google.com> Commit-Queue: Jiacheng Lu <lujc@google.com>