Remove JumpListIconsOld directory and set upper limit for delete attempts

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 fb8d14342f443f70ddd12bf7398fe7d822cf87a8..11985d082e34bfeb57bb89638801545fcd564503 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -79856,6 +79856,24 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <summary>The type of category clicked in the Windows Jumplist</summary>
 </histogram>
 
+<histogram name="WinJumplist.DeleteStatusJumpListIcons"
+    enum="JumplisticonsDeleteCategory">
+  <owner>chengx@chromium.org</owner>
+  <summary>
+    This metric records the detailed delete result of JumpListIcons directory.
+    Please refer to JumplisticonsDeleteCategory for more information.

[Ilya Sherman, 2017/03/21 20:56:45]

There is no need for the second sentence here -- it doesn't mean anything in the
context of the dashboard, which is where this will be viewed.  Ditto below.

[chengx, 2017/03/22 06:46:28]

Done.

+  </summary>
+</histogram>
+
+<histogram name="WinJumplist.DeleteStatusJumpListIconsOld"
+    enum="JumplisticonsDeleteCategory">
+  <owner>chengx@chromium.org</owner>
+  <summary>
+    This metric records the detailed delete result of JumpListIconsOld
+    directory. Please refer to JumplisticonsDeleteCategory for more information.
+  </summary>
+</histogram>
+
 <histogram name="WinJumplist.DetailedFolderMoveResults"
     enum="JumplistIconsDetailedFolderMoveCategory">
   <obsolete>
@@ -79893,6 +79911,10 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 
 <histogram name="WinJumplist.DetailedFolderResultsDeleteUpdated"
     enum="JumplistIconsDetailedFolderOperationDeleteUpdatedCategory">
+  <obsolete>
+    Obselete 03/20/2016. New metrics named WinJumplist.DeleteStatusJumpListIcons
+    and WinJumplist.DeleteStatusJumpListIconsOld are used instead.
+  </obsolete>
   <owner>chengx@chromium.org</owner>
   <summary>
     This metric is recorded when folders JumpListIcons and JumpListIconsOld get
@@ -97598,6 +97620,14 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </int>
 </enum>
 
+<enum name="JumplisticonsDeleteCategory" type="int">
+  <int value="0" label="Success"/>
+  <int value="1" label="Fail as folder name length exceeds MAX_PATH"/>
+  <int value="2" label="Fail as folder is read-only"/>
+  <int value="3" label="Fail to delete maximum files allowed with no failures"/>
+  <int value="4" label="Fail to delete maximum files allowed"/>

[Ilya Sherman, 2017/03/21 20:56:45]

I don't understand the difference between these two buckets, nor what either of
them means individually.  Please try to clarify these labels.  (Note: I'm not
necessarily asking you to write longer text; if you can find a brief way to
clearly label these, that would be best.)

[chengx, 2017/03/22 06:46:28]

Alright, I have renamed those two labels. Basically, I am trying to delete 100
icon files in a big icon pool using maximum 200 attempts. Label 3 (now 4) means
that we can delete 100 files with more than 100 attempts but less than 200
attempts. Therefore, there are some failures and the failure count is less than
100. Label 4 (now 5) means that we have attempted 200 times, but more than half
of them fail. Therefore, the goal of deleting 100 files is not achieved.

+</enum>
+
 <enum name="JumplistIconsDetailedFolderMoveCategory" type="int">
   <int value="0"
       label="DelTargetDir Succeed - MoveFileEx Succeed - CopyFile Succeed -