Remove MediaStreamDeviceThread in favor of using AudioThread.

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 47816ec9b4796c53d537e8c22ee49a0ee0a970f1..4580a1c3a9cbf9ebe853af01ed59ec09b536eb12 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -3546,6 +3546,10 @@ other types of suffix sets.
   <summary>Measures the time taken for AudioInputController::</summary>
 </histogram>
 
+<histogram name="Media.AudioInputDeviceManager" units="ms">
+  <summary>Measures the time taken for AudioInputDeviceManager::</summary>
+</histogram>
+
 <histogram name="Media.AudioOutputController" units="ms">
   <summary>Measures the time taken for AudioOutputController::</summary>
 </histogram>
@@ -3978,6 +3982,10 @@ other types of suffix sets.
   </summary>
 </histogram>
 
+<histogram name="Media.VideoCaptureManager" units="ms">
+  <summary>Measures the time taken for VideoCaptureManager::</summary>
+</histogram>
+
 <histogram name="Media.VideoCodec" enum="VideoCodec">
   <summary>Video codec used in HTML5 media.</summary>
 </histogram>
@@ -18718,6 +18726,14 @@ other types of suffix sets.
   <affected-histogram name="Media.AudioInputController"/>
 </fieldtrial>
 
+<fieldtrial name="MediaAudioInputDeviceManagerTime" separator=".">
+  <group name="OpenOnDeviceThreadTime"
+      label="Measures the time taken for OpenOnDeviceThread()."/>
+  <group name="EnumerateOnDeviceThreadTime"
+      label="Measures the time taken for EnumerateOnDeviceThread()."/>
+  <affected-histogram name="Media.AudioInputDeviceManager"/>
+</fieldtrial>
+
 <fieldtrial name="MediaAudioOutputControllerTime" separator=".">
   <group name="CloseTime" label="Measures the time taken for DoClose()."/>
   <group name="CreateTime" label="Measures the time taken for DoCreate()."/>
@@ -18730,6 +18746,16 @@ other types of suffix sets.
   <affected-histogram name="Media.AudioOutputController"/>
 </fieldtrial>
 
+<fieldtrial name="MediaVideoCaptureManagerTime" separator=".">
+  <group name="OnEnumerateDevicesTime"
+      label="Measures the time taken for OnEnumerateDevices()."/>
+  <group name="OnOpenTime" label="Measures the time taken for OnOpen()."/>
+  <group name="OnCloseTime" label="Measures the time taken for OnClose()."/>
+  <group name="OnStartTime" label="Measures the time taken for OnStart()."/>
+  <group name="OnStopTime" label="Measures the time taken for OnStop()."/>
+  <affected-histogram name="Media.VideoCaptureManager"/>
+</fieldtrial>
+
 <fieldtrial name="NetConnectivity" separator=".">
   <group name="53.100B" label="100 bytes of data on port 53."/>
   <group name="53.100B.NoProxy"