[autotest] Post processing script for suite time breakdown

This script measures nine stats for a suite run.
1. Net suite runtime.
2. Suite scheduling overhead.
3. Average scheduling overhead.
4. Average Queuing time.
5. Average Resetting time.
6. Average provisioning time.
7. Average Running time.
8. Average Parsing time.
9. Average Gathering time.

BUG=chromium:426118
TEST=run ./site_utils/collect_suite_time_stats.py on local machine

Change-Id: I8e4cd30cd0ce4fbb1801f277824a0c652f933f08
Reviewed-on: https://chromium-review.googlesource.com/227467
Reviewed-by: Fang Deng <fdeng@chromium.org>
Tested-by: Mungyung Ryu <mkryu@google.com>
Commit-Queue: Mungyung Ryu <mkryu@google.com>
5 files changed