GitLab

Add assert to check coverage file path have source root.

TBR=mmoroz@chromium.org

Bug: 784464, 836663
Change-Id: I09c05445b1a86de19ef41d40e7e6fa72ce361390
Reviewed-on: https://chromium-review.googlesource.com/1046151Reviewed-by: Abhishek Arya <inferno@chromium.org>
Reviewed-by: Yuke Liao <liaoyuke@chromium.org>
Commit-Queue: Abhishek Arya <inferno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#556357}