The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c2c95b761e7968b71b48e4afbeda38e1a50e176b

commit c2c95b761e7968b71b48e4afbeda38e1a50e176b
Author: Karan Bhatia <karandeepb@chromium.org>
Date: Wed Sep 12 03:21:50 2018

DocServer: Show correct availability for API's available on trunk.

Extension features on Chromium use "trunk" as the channel for features only
available when Chromium is build from source. However, the Docserver uses
"master" as the channel name to refer to trunk. This discrepancy causes the
Docserver to display incorrect availability for features available on trunk. Fix
this.

BUG= 883009 

Change-Id: Ibd909b23cc6110960eacb526728ccabd1829452f
Reviewed-on: https://chromium-review.googlesource.com/1220485
Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Commit-Queue: Karan Bhatia <karandeepb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#590586}
[modify] https://crrev.com/c2c95b761e7968b71b48e4afbeda38e1a50e176b/chrome/common/extensions/docs/server2/app.yaml
[modify] https://crrev.com/c2c95b761e7968b71b48e4afbeda38e1a50e176b/chrome/common/extensions/docs/server2/availability_finder.py
[modify] https://crrev.com/c2c95b761e7968b71b48e4afbeda38e1a50e176b/chrome/common/extensions/docs/server2/availability_finder_test.py
[modify] https://crrev.com/c2c95b761e7968b71b48e4afbeda38e1a50e176b/chrome/common/extensions/docs/server2/test_data/canned_data.py

Next action: Update the served version.

The NextAction date has arrived: 2018-09-12

Fixed, https://developer.chrome.com/extensions/declarativeNetRequest shows the correct messaging.