Add updated documentation for debugging data stoppage alerts.

tools/perf/docs/perf_regression_sheriffing.md

Index: tools/perf/docs/perf_regression_sheriffing.md
diff --git a/tools/perf/docs/perf_regression_sheriffing.md b/tools/perf/docs/perf_regression_sheriffing.md
index 6373fafb7060f2375b4518738d7ad7747ed4a34c..17a21e2a25edc151334b8f773030e8dd65d5c336 100644
--- a/tools/perf/docs/perf_regression_sheriffing.md
+++ b/tools/perf/docs/perf_regression_sheriffing.md
@@ -25,8 +25,8 @@ internal waterfalls.
 Pick up **Chromium Perf Sheriff** from "Select an item ▼" drop down menu. There
 are two tables of alerts that may be shown:
 
- * "Performance Alerts", which you should triage, and
- * "Data Stoppage Alerts", which you can ignore.
+ * "Performance Alerts"
+ * "Data Stoppage Alerts"
 
 For either type of alert, if there are no currently pending alerts, then the
 table won't be shown.
@@ -86,39 +86,9 @@ below it the dashboard shows graphs of all the alerts checked in that table.
 Data stoppage alerts are listed on the
 [perf dashboard alerts page](https://chromeperf.appspot.com/alerts). Whenever
 the dashboard is monitoring a metric, and that metric stops sending data, an
-alert is fired. Some of these alerts are expected:
-
-   * When a telemetry benchmark is disabled, we get a data stoppage alert.
-     Check the [code for the benchmark](https://code.google.com/p/chromium/codesearch#chromium/src/tools/perf/benchmarks/)
-     to see if it has been disabled, and if so associate the alert with the
-     bug for the disable.
-   * When a bot has been turned down. These should be announced to
-     perf-sheriffs@chromium.org, but if you can't find the bot on
-     [the waterfall](https://uberchromegw.corp.google.com/i/chromium.perf/) and
-     you didn't see the announcement, double check in the speed infra chat.
-     Ideally these will be associated with the bug for the bot turndown, but
-     it's okay to mark them invalid if you can't find the bug.
-     You can check the
-     [recipe](https://chromium.googlesource.com/chromium/tools/build/+/master/scripts/slave/recipe_modules/chromium_tests/chromium_perf.py)
-     to find a corresponding bot name for waterfall with one for dashboard.
-
-If there doesn't seem to be a valid reason for the alert, file a bug on it
-using the perf dashboard, and cc [the owner](http://go/perf-owners). Then do
-some diagnosis:
-
-   * Look at the perf dashboard graph to see the last revision we got data for,
-     and note that in the bug. Click on the `buildbot stdio` link in the tooltip
-     to find the buildbot status page for the last good build, and increment
-     the build number to get the first build with no data, and note that in the
-     bug as well. Check for any changes to the test in the revision range.
-   * Go to the buildbot status page of the bot which should be running the test.
-     Is it running the test? If not, note that in the bug.
-   * If it is running the test and the test is failing, diagnose as a test
-     failure.
-   * If it is running the test and the test is passing, check the `json.output`
-     link on the buildbot status page for the test. This is the data the test
-     sent to the perf dashboard. Are there null values? Sometimes it lists a
-     reason as well. Please put your finding in the bug.
+alert is fired. See
+[triaging data stoppage alerts](triaging_data_stoppage_alerts.md) for more
+details.
 
 ## Follow up on Performance Regressions