enable_reporting=true adds 25kB or about 1% to the size of a release build of libcronet for ARM 32-bit.  Seems reasonable to me.

Cool. I can also try condensing some overly-factored-out bits of the code and see if I can get that down a bit.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ae5d1d8e11a5df4e62b5f53cb14ffd0c7a5c0fa9

commit ae5d1d8e11a5df4e62b5f53cb14ffd0c7a5c0fa9
Author: Misha Efimov <mef@chromium.org>
Date: Thu Apr 05 05:56:22 2018

[Cronet] Enable reporting feature on Android.

Bug:  828899 
Cq-Include-Trybots: master.tryserver.chromium.android:android_cronet_tester;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: I14000553e3164529bcf11d7aadf38ceb8f76c01e
Reviewed-on: https://chromium-review.googlesource.com/995636
Reviewed-by: John Budorick <jbudorick@chromium.org>
Reviewed-by: Julia Tuttle <juliatuttle@chromium.org>
Reviewed-by: Paul Jensen <pauljensen@chromium.org>
Commit-Queue: Misha Efimov <mef@chromium.org>
Cr-Commit-Position: refs/heads/master@{#548347}
[modify] https://crrev.com/ae5d1d8e11a5df4e62b5f53cb14ffd0c7a5c0fa9/components/cronet/tools/cr_cronet.py
[modify] https://crrev.com/ae5d1d8e11a5df4e62b5f53cb14ffd0c7a5c0fa9/tools/mb/mb_config.pyl

Moving to Doug, who is doing the work.

This is live in Cronet, including test cases that verify that the Reporting and NEL stacks work as expected.

Um, but those tests still fail and are disabled in internal system, right?

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/tools/build/+/8bd87b4a1e10eec2bea23292da3ddec5f97ee604

commit 8bd87b4a1e10eec2bea23292da3ddec5f97ee604
Author: Misha Efimov <mef@chromium.org>
Date: Wed Oct 17 15:35:47 2018

[Cronet] Enable NEL reporting in official builds.

Bug:  828899 
Change-Id: Ic0c2bd646d4dbf4c4e6352842c12752cd9232531

Recipe-Nontrivial-Roll: build_limited_scripts_slave
Change-Id: Ic0c2bd646d4dbf4c4e6352842c12752cd9232531
Reviewed-on: https://chromium-review.googlesource.com/c/1284872
Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: Misha Efimov <mef@chromium.org>

[modify] https://crrev.com/8bd87b4a1e10eec2bea23292da3ddec5f97ee604/scripts/slave/recipe_modules/chromium_android/chromium_config.py
[modify] https://crrev.com/8bd87b4a1e10eec2bea23292da3ddec5f97ee604/scripts/slave/recipe_modules/cronet/examples/full.expected/gn_test.json