[Pinpoint] Update Speed documentation.

 - Update the dialog image.
 - Update the arguments to match the new UI.
 - Add information about story tags.

(To see how the markdown file will look, click the perf_trybots.md
file link and then click the "gitiles" link next to the patchset number.)

Bug: 1023451, 1059913
Change-Id: Ie019338f64d3fc0649cc7fd63d7a84bd29b756e0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2112579
Reviewed-by: Wenbin Zhang <wenbinzhang@google.com>
Commit-Queue: Caleb Rouleau <crouleau@chromium.org>
Cr-Commit-Position: refs/heads/master@{#752612}

docs/speed/perf_trybots.md

@@ -29,20 +29,24 @@ You should see the following dialog popup:
 
 ![Perf Try Dialog](images/pinpoint-perf-try-dialog.png)
 
-
-**Build Arguments**| **Description**
+**Benchmark Configuration**| **Description**
 --- | ---
-Bug ID | (optional) A bug ID. Pinpoint will post updates on the bug.
-Gerrit URL | The patch you want to run the benchmark on. Patches in dependent repos (e.g. v8, skia) are supported.
 Bot | The device type to run the test on. All hardware configurations in our perf lab are supported.
+Benchmark | A telemetry benchmark. E.g. `system_health.common_desktop`<br><br>All the telemetry benchmarks are supported by the perf trybots. To get a full list, run `tools/perf/run_benchmark list`<br><br>To learn more about the benchmarks, you can read about the [system health benchmarks](https://docs.google.com/document/d/1BM_6lBrPzpMNMtcyi2NFKGIzmzIQ1oH3OlNG27kDGNU/edit?ts=57e92782), which test Chrome's performance at a high level, and the [benchmark harnesses](https://docs.google.com/spreadsheets/d/1ZdQ9OHqEjF5v8dqNjd7lGUjJnK6sgi8MiqO7eZVMgD0/edit#gid=0), which cover more specific areas.
+Story | (optional) A specific story from the benchmark to run. Note that if the story you want isn't on the dropdown it could be because the story is new and so the Chromeperf dashboard database doesn't know about it yet. In that case you can still free-form type the exact story name into the field.
+Story Tags | (optional) A list of story tags. All stories in the given benchmark that match any of the tags will be run.
+Extra Test Arguments | (optional) Extra arguments for the test. E.g. `--extra-chrome-categories="foo,bar"`<br><br>To see all arguments, run `tools/perf/run_benchmark run --help`
 
-<br>
+Note that you must provide either a Story or a Story Tag for Pinpoint to run.
+Per [this explanation](https://bugs.chromium.org/p/chromium/issues/detail?id=1017811#c6), running an entire benchmark on Pinpoint can cause significant problems if the benchmark is large. For this reason, some small benchmarks have an 'all' tag available that applies to all the stories in the benchmark, so please use that tag to run all the stories for a small benchmark. Please see [this bug](https://bugs.chromium.org/p/chromium/issues/detail?id=1023451) for details on work to add the 'all' tag to more benchmarks. If you want to run a large benchmark, consider choosing one of the tags that benchmark provides to select a subset of the available stories for that benchmark.
 
-**Test Arguments**| **Description**
+<br><br>
+
+**Job Configuration**| **Description**
 --- | ---
-Benchmark | A telemetry benchmark. E.g. `system_health.common_desktop`<br><br>All the telemetry benchmarks are supported by the perf trybots. To get a full list, run `tools/perf/run_benchmark list`<br><br>To learn more about the benchmarks, you can read about the [system health benchmarks](https://docs.google.com/document/d/1BM_6lBrPzpMNMtcyi2NFKGIzmzIQ1oH3OlNG27kDGNU/edit?ts=57e92782), which test Chrome's performance at a high level, and the [benchmark harnesses](https://docs.google.com/spreadsheets/d/1ZdQ9OHqEjF5v8dqNjd7lGUjJnK6sgi8MiqO7eZVMgD0/edit#gid=0), which cover more specific areas.
-Story | (optional) A specific story from the benchmark to run.
-Extra Test Arguments | (optional) Extra arguments for the test. E.g. `--extra-chrome-categories="foo,bar"`<br><br>To see all arguments, run `tools/perf/run_benchmark run --help`
+Base Git Hash | The Git Hash that you want to put your Gerrit patch on top of.
+Gerrit URL | The patch you want to run the benchmark on. Patches in dependent repos (e.g. v8, skia) are supported. Pinpoint will also post updates on the Gerrit comment list.
+Bug ID | (optional) A bug ID. Pinpoint will post updates on the bug.
 
 ## Interpreting the results