Report timing statistics for audio controller methods via UMA.

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 fe74e916040867cd9fb5bb3a5ec3373e2e413133..b04f0f80fff34263c69bca5e17ebc6062a5c80ad 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -1012,6 +1012,55 @@ other types of suffix sets.
   <summary>The version of glibc used. (Linux only)</summary>
 </histogram>
 
+<histogram name="Media.AudioInputController.CloseTime" units="ms">

[jar (doing other things), 2013/05/14 01:43:57]

nit: These all look almost the same... and you can use the XML feature in this
file to wirte them very compactly.  Just define one histogram:
histogram name="Media.AudioInputController" units="ms">
  <summary>
  Measures the time taken for AudioInputController::
  </summary>
  </histogram>

Then define a FieldTrial  with separator="." and extensions containing:
"CloseTime"   "DoClose()."
"CreateTime"  "DoCreate()."
...
"PlayTime"   "DoPlay().  Technically only the worker method
AudioOutputController::PollAndStartIfDataReady()."

Take a look at <FieldTrial...> later in the file.

[DaleCurtis, 2013/05/15 01:30:31]

Done.

+  <summary>
+    Measures the time taken for AudioInputController::DoClose().
+  </summary>
+</histogram>
+
+<histogram name="Media.AudioInputController.CreateTime" units="ms">
+  <summary>
+    Measures the time taken for AudioInputController::DoCreate().
+  </summary>
+</histogram>
+
+<histogram name="Media.AudioInputController.RecordTime" units="ms">
+  <summary>
+    Measures the time taken for AudioInputController::DoRecord().
+  </summary>
+</histogram>
+
+<histogram name="Media.AudioOutputController.CloseTime" units="ms">
+  <summary>
+    Measures the time taken for AudioOutputController::DoClose().
+  </summary>
+</histogram>
+
+<histogram name="Media.AudioOutputController.CreateTime" units="ms">
+  <summary>
+    Measures the time taken for AudioOutputController::DoCreate().
+  </summary>
+</histogram>
+
+<histogram name="Media.AudioOutputController.DeviceChangeTime" units="ms">
+  <summary>
+    Measures the time taken for AudioOutputController::OnDeviceChange().
+  </summary>
+</histogram>
+
+<histogram name="Media.AudioOutputController.PauseTime" units="ms">
+  <summary>
+    Measures the time taken for AudioOutputController::DoPause().
+  </summary>
+</histogram>
+
+<histogram name="Media.AudioOutputController.PlayTime" units="ms">
+  <summary>
+    Measures the time taken for AudioOutputController::DoPlay().  Technically
+    only the worker method AudioOutputController::PollAndStartIfDataReady().
+  </summary>
+</histogram>
+
 <histogram name="Media.AudioRendererEvents" enum="AudioRendererEvents">
   <summary>Captures statistics for various AudioRendererImpl events.</summary>
 </histogram>