cct_benchmark: Target CSV more precisely in the log

We added more log messages in MainActivity.java, which would be grabbed
by the python script, but would not provide the proper line in the CSV.
To address this make a dedicated prefix: CUSTOMTABSBENCHCSV.

Bug: 929926
Change-Id: If5891931609dc89017eb163467f4d6f8dc70c43c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1667582
Reviewed-by: Benoit L <lizeb@chromium.org>
Commit-Queue: Egor Pasko <pasko@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#671614}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 552a276865ffa6f544cc7fdc928df4e72d3a48ed
2 files changed