The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/66da1730c0ed93c82f8921227e2f671a514cfaf1

commit 66da1730c0ed93c82f8921227e2f671a514cfaf1
Author: Yuke Liao <liaoyuke@chromium.org>
Date: Tue Dec 05 22:19:42 2017

[Coverage] Support filtering results by list of directories or files

This CL adds support to filter code coverage results by list of
directories or files so that the script can run faster without having
to generate a report for every executed file.

Bug:  789691 
Change-Id: I2e954872b7f1113cd04b8e609ffdabf0578db762
Reviewed-on: https://chromium-review.googlesource.com/809295
Commit-Queue: Yuke Liao <liaoyuke@chromium.org>
Reviewed-by: Abhishek Arya <inferno@chromium.org>
Reviewed-by: Max Moroz <mmoroz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#521857}
[modify] https://crrev.com/66da1730c0ed93c82f8921227e2f671a514cfaf1/tools/code_coverage/coverage.py