Add documentation for SkiaLab

site/dev/testing/buildbot.md

 Skia Buildbots
 ==============
 
 Overview
 --------
 
 Like the Chromium team, the Skia team uses [buildbot](http://trac.buildbot.net/)
 to run continuous builds and tests.
 
 Here is a link to our main status page: https://status.skia.org/
 
-There are also Skia client, compile, Android, and FYI console pages for a detailed
-view of those results: 
+There are also buildbot console pages for a detailed view of those results:
   
-  Externally-facing: http://build.chromium.org/p/client.skia/console
-  
-  Internally-facing: http://chromegw.corp.google.com/i/client.skia/console
-                     http://chromegw.corp.google.com/i/client.skia.internal/console
-                     \(only visible internally\)
+  Externally-facing:
+
+* http://build.chromium.org/p/client.skia/console
+* http://build.chromium.org/p/client.skia.android/console
+* http://build.chromium.org/p/client.skia.compile/console
+* http://build.chromium.org/p/client.skia.fyi/console
+
+  Internally-facing:
+
+* http://uberchromegw.corp.google.com/i/client.skia/console
+* http://uberchromegw.corp.google.com/i/client.skia.android/console
+* http://uberchromegw.corp.google.com/i/client.skia.compile/console
+* http://uberchromegw.corp.google.com/i/client.skia.fyi/console
+* http://uberchromegw.corp.google.com/i/client.skia.internal/console
+
 
 Architecture
 ------------
 
 The buildbot system consists of these elements: \(see
 http://buildbot.net/buildbot/docs/current/manual/introduction.html#system-architecture
 for more detail\) 
 
-* builder
+* Buildbot Master
 
-    * one repeatable build and/or test configuration on a given platform.
-    * each builder maintains its own local checkout of the Skia repo
-    * only one builder is running at any given time on any single buildslave; otherwise,
-       different builders could interfere with each other's performance numbers
+    * Watches for new commits to land in the Skia repository
+      \(https://skia.googlesource.com/skia\)
+    * Whenever a new commit lands, it triggers a **Build** on each **Builder**
+      to test the new revision.
+    * Serves up status pages whenever anybody requests them
 
-* buildbot master
+* Build
+
+    * One run of a particular **Builder**, at a particular code revision.
+    * "Build" is sort of a misnomer; it's just a list of steps (typically shell
+      commands) which are run by the **Buildslave** process on the host
+      machine, and those may include compiling and running code as well as
+      arbitrary other commands.
+
+* Builder
+
+    * One repeatable build and/or test configuration on a given platform. The
+      Builder is basically a blueprint which provides logic to determine which
+      steps to run within a Build.
+
+* Buildslave \(or "buildbot slave"\)
     
-    * watches for new commits to land in the Skia repository 
-      \(https://skia.googlesource.com/skia\) 
-    * whenever a new commit lands, it tells buildbot slaves to start building and 
-      testing the latest revision 
-    * serves up status pages whenever anybody requests them
-
-* buildslave \(or "buildbot slave"\)
-    
-    * a process on a machine that builds and runs code as directed by the buildbot 
-      master
-    * one or more builders run on each buildslave
-
-* build
-
-    * one run of a particular builder, at a particular code revision
+    * A process running on a host machine that builds and runs code as directed
+      by the Buildbot Master.
+    * One or more Builders may run on a given Buildslave, but only one runs at
+      a time.
+    * One or more Buildslaves may run on a given host machine.
 
 
 Status View
 ------------
 
 The status view shows a table with builders, grouped by test type and platform,
 on the X-axis and commits on the Y-axis.  The cells are colored according to
 the status of the build for each commit: green indicates success, red indicates
 failure, light orange indicates an in-progress build, and white indicates that
 no build has started yet for a given revision. Commits are listed by author, and
 the branch on which the commit was made is shown on the very left.
 
 For more detail, you can click on an individual cell to get a summary of the
 steps which ran for that build.  You can also click one of the white bars at
 the top of each column to see a summary of recent builds for a given builder.