Time out jumplist update for very slow or busy OS

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 5c644c89bdedc7494b375c9e31d5ee583f8da387..08ffa20997af4a3676841598ed482c945998d2e4 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -81790,6 +81790,9 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 </histogram>
 
 <histogram name="WinJumplist.CreateIconFilesCount">
+  <obsolete>
+    Obsolete 04/20/2017 as we are no long recording this metric.
+  </obsolete>
   <owner>chengx@chromium.org</owner>
   <summary>
     Count of jumplist icons that will be created per jumplist update. It is
@@ -81940,6 +81943,9 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 </histogram>
 
 <histogram name="WinJumplist.UpdateJumpListDuration" units="ms">
+  <obsolete>
+    Obsolete 04/20/2017 as it's no longer accurate due to the code change.
+  </obsolete>
   <owner>chengx@chromium.org</owner>
   <summary>
     Time spent in UpdateJumpList(). This method is called whenever there is a