It looks like, in Chrome, this work is done by the FieldTrialSynchronizer, with a call to SetVariationsListCrashKeys():

https://cs.chromium.org/chromium/src/chrome/browser/metrics/field_trial_synchronizer.cc?l=33

Currently we don't have an equivalent of the synchronizer in WebView, and I don't think we need to create one for this. Chrome creates the object here:

https://cs.chromium.org/chromium/src/chrome/browser/chrome_browser_main.cc?l=707

and the important work is done in the constructor. We may be able to get away with just adding a direct call to variations::SetVariationListCrashKeys() in AwFieldTrialCreator's SetupFieldTrials().

Assigning to owner. Please triage as appropriate.

This is a critical feature for Finch, as people who experiments Finch would want to collect stability data as well as other metrics.

Hazem is able to take this.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/713df1886f5c891d07c5a1ca012f83e3a698ead6

commit 713df1886f5c891d07c5a1ca012f83e3a698ead6
Author: Hazem Ashmawy <hazems@chromium.org>
Date: Thu Nov 01 17:12:51 2018

[aw] Add Finch experiments to Webview minidump

Add Finch Experiments info aka variations crash keys to Webview minidump. The keys are "variations" and "num-experiments".

Bug:  758450 
Change-Id: Ib3bc7b872c0ff88eb404595496a9084f1d123ea9
Reviewed-on: https://chromium-review.googlesource.com/c/1305953
Commit-Queue: Hazem Ashmawy <hazems@chromium.org>
Reviewed-by: Tobias Sargeant <tobiasjs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#604622}
[modify] https://crrev.com/713df1886f5c891d07c5a1ca012f83e3a698ead6/android_webview/browser/aw_field_trial_creator.cc
[modify] https://crrev.com/713df1886f5c891d07c5a1ca012f83e3a698ead6/android_webview/common/crash_reporter/crash_keys.cc

This change is landed in version 72.0.3599.0. The "Experiments" field in chrome crash dashboard now shows experiments IDs and count for webview crashes.