How do I get that lint warning? I can't see it when just compiling WebView.

It will be visible once this lands and you remove the suppression: https://chromium-review.googlesource.com/c/chromium/src/+/652964

For now removing it from suppressions.xml will cause a lot of breakages (as seen in that CL).

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e641faa1afd8b63f8ea1b67bac2527cd38def3ed

commit e641faa1afd8b63f8ea1b67bac2527cd38def3ed
Author: Gustav Sennton <gsennton@google.com>
Date: Wed Sep 13 17:20:34 2017

[WebView] Replace use of JobScheduler.getPendingJob (API level 24).

AwVariationsConfigurationService uses JobScheduler.getPendingJob to
check whether a specific job is pending. This method was introduced in
Android version 24, but WebView supports version 21+, so replace the use
of JobScheduler.getPendingJob with JobScheduler.getAllPendingJobs instead.

Bug:  762607 
Change-Id: Ia05815e73690ec0deff78d8d78b04d63376ec255
Reviewed-on: https://chromium-review.googlesource.com/664722
Commit-Queue: Gustav Sennton <gsennton@chromium.org>
Reviewed-by: Tobias Sargeant <tobiasjs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#501672}
[modify] https://crrev.com/e641faa1afd8b63f8ea1b67bac2527cd38def3ed/android_webview/java/src/org/chromium/android_webview/variations/AwVariationsConfigurationService.java