Implement accumulatative composition for filter

This CL implements the accumulative operation described in
https://github.com/w3c/fxtf-drafts/issues/371.

Bug: 788440
Change-Id: I0ecf0a29110650ef5166b92bc0b8f1396c4b18dd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1830568
Commit-Queue: Stephen McGruer <smcgruer@chromium.org>
Commit-Queue: Alan Cutter <alancutter@chromium.org>
Reviewed-by: Alan Cutter <alancutter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#701075}
22 files changed