Remove worker pool names from TaskScheduler.TaskLatency.* histograms.

tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 456e5f4a83e30f559265773946e25da076915bbf..f21fb0d2b2f60112de832d24a1d6c2af61d029ab 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -115523,6 +115523,16 @@ value.
   <affected-histogram name="Tabs.SwitchFromUserLatency"/>
 </histogram_suffixes>
 
+<histogram_suffixes name="TaskSchedulerMayBlock" separator=".">
+  <suffix name="MayBlock"
+      label="Applies to tasks posted with MayBlock() or
+             WithBaseSyncPrimitives()."/>
+  <affected-histogram name="TaskScheduler.TaskLatency.BackgroundTaskPriority"/>
+  <affected-histogram
+      name="TaskScheduler.TaskLatency.UserBlockingTaskPriority"/>
+  <affected-histogram name="TaskScheduler.TaskLatency.UserVisibleTaskPriority"/>
+</histogram_suffixes>
+
 <histogram_suffixes name="TaskSchedulerTaskPriority" separator=".">
   <suffix name="BackgroundTaskPriority"
       label="Applies to tasks posted with a BACKGROUND priority."/>
@@ -115530,10 +115540,27 @@ value.
       label="Applies to tasks posted with a USER_VISIBLE priority."/>
   <suffix name="UserBlockingTaskPriority"
       label="Applies to tasks posted with a USER_BLOCKING priority."/>
-  <affected-histogram name="TaskScheduler.TaskLatency.BackgroundFileIOPool"/>
-  <affected-histogram name="TaskScheduler.TaskLatency.BackgroundPool"/>
-  <affected-histogram name="TaskScheduler.TaskLatency.ForegroundFileIOPool"/>
-  <affected-histogram name="TaskScheduler.TaskLatency.ForegroundPool"/>
+  <affected-histogram name="TaskScheduler.TaskLatency"/>
+  <affected-histogram name="TaskScheduler.TaskLatency.BackgroundFileIOPool">
+    <obsolete>
+      Deprecated 12/2016. Pool name removed from task latency histogram name.
+    </obsolete>
+  </affected-histogram>
+  <affected-histogram name="TaskScheduler.TaskLatency.BackgroundPool">
+    <obsolete>
+      Deprecated 12/2016. Pool name removed from task latency histogram name.
+    </obsolete>
+  </affected-histogram>
+  <affected-histogram name="TaskScheduler.TaskLatency.ForegroundFileIOPool">
+    <obsolete>
+      Deprecated 12/2016. Pool name removed from task latency histogram name.
+    </obsolete>
+  </affected-histogram>
+  <affected-histogram name="TaskScheduler.TaskLatency.ForegroundPool">
+    <obsolete>
+      Deprecated 12/2016. Pool name removed from task latency histogram name.
+    </obsolete>
+  </affected-histogram>
 </histogram_suffixes>
 
 <histogram_suffixes name="TaskSchedulerWorkerPool" separator=".">
@@ -115546,7 +115573,11 @@ value.
   <affected-histogram name="TaskScheduler.DetachDuration"/>
   <affected-histogram name="TaskScheduler.NumTasksBeforeDetach"/>
   <affected-histogram name="TaskScheduler.NumTasksBetweenWaits"/>

[gab, 2017/01/05 19:25:46]

These are still suffixed? Or do we intend to change them too?

[fdoray, 2017/01/05 20:13:38]

I removed pool suffixes from TaskLatency histograms because values are
associated with individual tasks. Not having pool suffixes for TaskLatency allow
us to keep track of latencies with different pool implementations.

I think we should keep pool suffixes for
DetachDuration/NumTasksBeforeDetach/NumTasksBetweenWaits. These histograms are
specific to the current implementation (they don't make sense with a
TaskScheduler backed by the Windows Thread Pool or GCD). The values don't refer
to individual tasks.

[gab, 2017/01/05 22:16:36]

Right, sgtm.

-  <affected-histogram name="TaskScheduler.TaskLatency"/>
+  <affected-histogram name="TaskScheduler.TaskLatency">
+    <obsolete>
+      Deprecated 12/2016. Pool name removed from task latency histogram name.
+    </obsolete>
+  </affected-histogram>
 </histogram_suffixes>
 
 <histogram_suffixes name="ThreadWatcher" separator=".">