docs: Revise Tast test disabling options.

This should hopefully make it clear to sheriffs that either option is
valid.

Change-Id: Ida41d139dfdb09be3067228d6a05cb3b46806562
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2159605Reviewed-by: Stephen Martinis <martiniss@chromium.org>
Commit-Queue: Ben Pastene <bpastene@chromium.org>
Cr-Commit-Position: refs/heads/master@{#761076}

docs/testing/chromeos_debugging_tips.md

@@ -30,13 +30,19 @@ the test step's [shard #0 isolated out] link. From there, view the various
 `log/chrome/...` or `log/ui/...` text files and you should find some with
 browser [crashes and stack traces].
 
-To disable a test on Chrome's builders, the preferred method is to add the
-`informational` attribute to the test's definition (see [Tast attributes] for
-more info). Note that this requires a full Chrome OS checkout. If that's not an
-option, or if it needs to be disabled ASAP, you can add it to the list of
+There a couple ways to disable a test on Chrome's builders:
+- **With a full CrOS checkout**: If you have a full CrOS checkout, you can add
+the `informational` attribute to the test's definition (see [Tast attributes]
+for more info). This can take time (ie: many hours) to land and propagate onto
+Chrome's builders. So if you need the test disabled ASAP, consult the next
+option.
+- **With only a Chromium checkout**: You can also add the test to the list of
 disabled tests for the step's GN target. For example, to disable a test in the
 `chrome_all_tast_tests` step, add it to [this list].
 
+In both cases, please make sure a bug is filed for the test, and route it to
+the appropriate owners.
+
 ## Telemetry
 
 >TODO: Add instructions for debugging telemetry failures.