Clean up RasterInterface command buffer functions

1- remove stale entries from build_raster_cmd_buffer.py
2- remove GenSyncTokenCHROMIUM which is unused outside of tests

Bug: None
Change-Id: I34d0f8b59e68f7eb34bc24db98ca57382272d316
Reviewed-on: https://chromium-review.googlesource.com/c/1407739
Reviewed-by: Jonathan Backer <backer@chromium.org>
Commit-Queue: Antoine Labour <piman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#622524}
10 files changed