Revert "Adding the following stylus metrics:"

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 ef8b538d5cad4495167b0ce9e06f40bd624e96c4..cf4ee2a7a31a152e1274cb305a59d0adc7367bae 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -12759,20 +12759,6 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
-<histogram name="Event.DownEventCount.PerFormFactor" enum="DownEventFormFactor">
-  <owner>xiaoyinh@chromium.org</owner>
-  <summary>
-    Counts the number of down events generated by clamshell/touchview.
-  </summary>
-</histogram>
-
-<histogram name="Event.DownEventCount.PerInput" enum="DownEventSource">
-  <owner>xiaoyinh@chromium.org</owner>
-  <summary>
-    Counts the number of down events generated by Mouse/Touch/Stylus.
-  </summary>
-</histogram>
-
 <histogram name="Event.DragDrop.Cancel" enum="DragDropEventSource">
   <owner>mfomitchev@chromium.org</owner>
   <summary>
@@ -74095,18 +74081,6 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="2" label="GET_NON_CACHABLE"/>
 </enum>
 
-<enum name="DownEventFormFactor" type="int">
-  <int value="0" label="Clamshell"/>
-  <int value="1" label="Touchview"/>
-</enum>
-
-<enum name="DownEventSource" type="int">
-  <int value="0" label="Unknown"/>
-  <int value="1" label="Mouse"/>
-  <int value="2" label="Stylus"/>
-  <int value="3" label="Touch"/>
-</enum>
-
 <enum name="DownloadContentDisposition" type="int">
   <int value="0" label="Content-Disposition header present"/>
   <int value="1" label="Valid"/>