Add some speed documentation:

docs/speed/how_does_chrome_measure_performance.md

+# How Chrome Measures Performance
+
+Chrome collects performance data both in the lab, and from end users. There are
+thousands of individual metrics. This is an overview of how to sort through
+them at a high level.
+
+## Tracks and Metrics
+
+At a high level, performance work in Chrome is categorized into **tracks**,
+like loading, memory, and power. Each track has high-level metrics associated
+with it.
+
+  * **[An overview of tracks](performance_tracks.md)**: lists the tracks and key contact points.
+  * **[Speed Launch Metrics](https://docs.google.com/document/d/1Ww487ZskJ-xBmJGwPO-XPz_QcJvw-kSNffm0nPhVpj8/edit):
+    the important high-level metrics we measure for each track.
+
+## Laboratory Metrics
+
+Chrome has multiple performance labs in which benchmarks are run on continuous
+builds to pinpoint performance regressions down to individual changelists.
+
+### The chromium.perf lab
+
+The main lab for performance monitoring is chromium.perf. It continuously tests
+chromium commits and is monitored by the perf sheriff rotation.
+
+  * **[What is the perf waterfall?](perf_waterfall.md)** An overview of the
+    waterfall that runs the continuous build.
+  * **[How telemetry works](https://github.com/catapult-project/catapult/blob/master/telemetry/README.md):
+    An overview of telemetry, our performance testing harness.
+  * **[How perf bisects work](bisects.md): An overview of the bisect bots,
+    which narrow down regressions over a CL range to a specific commit.
+  * **Benchmarks*
+    * **[Benchmark Policy](https://docs.google.com/document/d/1ni2MIeVnlH4bTj4yvEDMVNxgL73PqK_O9_NUm3NW3BA/edit)**:
+      An overview of the benchmark harnesses available in Chrome, and how to
+      find the right place to add a new test case.
+    * **[System health benchmarks](https://docs.google.com/document/d/1BM_6lBrPzpMNMtcyi2NFKGIzmzIQ1oH3OlNG27kDGNU/edit?ts=57e92782)**:
+      The system health benchmarks measure the speed launch metrics on
+      real-world web use scenarios.
+  * **[How to run on perf trybots](perf_trybots.md)**: Have an unsubmitted
+    CL and want to run benchmarks on it? Need to try a variety of hardware and
+    operating systems? Use the perf trybots.
+  * **[How to run telemetry locally](https://github.com/catapult-project/catapult/blob/master/telemetry/docs/run_benchmarks_locally.md)**:
+    Instructions on running telemetry benchmarks on your local machine.
+  * **[List of platforms in the lab](perf_lab_platforms.md)**: Devices,
+    configurations, and OSes the chromium.perf lab tests on.
+
+### Other performance labs
+
+There are several other performance labs for specialized use:
+
+  * **[Lab Spotlight: AV Lab (Googlers only)](http://goto.google.com/av-analysis-service)**:
+    Learn all about audio/video quality testing.
+  * **[Lab Spotlight: Cluster telemetry](https://docs.google.com/document/d/1GhqosQcwsy6F-eBAmFn_ITDF7_Iv_rY9FhCKwAnk9qQ/edit)**:
+    Need to run a performance test over thousands of pages? Check out cluster
+    telemetry!
+
+## End-user metrics
+
+The **[Speed Launch Metrics](https://docs.google.com/document/d/1Ww487ZskJ-xBmJGwPO-XPz_QcJvw-kSNffm0nPhVpj8/edit)**
+doc explains metrics available in UMA for end user performance. If you want to
+test how your change impacts these metrics for end users, you'll probably want
+to **[Run a Finch Trial](http://goto.google.com/finch101)**.