[Content suggestions] Report updates in the UI to UMA - cleanup

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 09367e435df709c6cd4f1ac068396710ef127d6f..a4f386d03dbcd5f3642d3be68e8d40cecb4ef062 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -39364,12 +39364,37 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 
 <histogram name="NewTabPage.ContentSuggestions.UIUpdateResult"
     enum="ContentSuggestionsUIUpdateResult">
+  <obsolete>

[jkrcal, 2017/01/20 18:09:17]

Robert, could we actually do it without renaming and obsoleting the previous
histogram (given it is not even one day old)? Actually, the question has two
levels:
 - is changing a very fresh histogram generally possible?
 - if so, is it possible when there was a branch point, in between? ;)

+    Replaced by NewTabPage.ContentSuggestions.UIUpdateResult2 in January 2017.
+  </obsolete>
   <owner>jkrcal@chromium.org</owner>
   <summary>
     Android: The result of updating the list of content suggestions in the UI.
   </summary>
 </histogram>
 
+<histogram name="NewTabPage.ContentSuggestions.UIUpdateResult2"
+    enum="ContentSuggestionsUIUpdateResult2">
+  <owner>jkrcal@chromium.org</owner>
+  <summary>
+    Android: The result of updating the list of content suggestions in one UI
+    section.
+  </summary>
+</histogram>
+
+<histogram
+    name="NewTabPage.ContentSuggestions.UIUpdateSuccessNumberOfSuggestionsSeen"
+    units="suggestions">
+  <owner>jkrcal@chromium.org</owner>
+  <summary>
+    Android: The number of content suggestions that have been seen by the user
+    in the UI section before the section was successfully updated. The seen
+    suggestions were not removed in the update so that we do not change visible
+    parts of the UI. This histogram is only recorded when the UIUpdateResult2 is
+    &quot;Success (some suggestions replaced)&quot;.
+  </summary>
+</histogram>
+
 <histogram name="NewTabPage.ContentSuggestions.UsageTimeLocal">
   <owner>markusheintz@chromium.org</owner>
   <summary>
@@ -81676,6 +81701,9 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 </enum>
 
 <enum name="ContentSuggestionsUIUpdateResult" type="int">
+  <obsolete>
+    Superseded by ContentSuggestionsUIUpdateResult2 in January 2017.
+  </obsolete>
   <int value="0" label="Success (appended)"/>
   <int value="1" label="Success (no suggestion seen)"/>
   <int value="2" label="Success (1 suggestion seen)"/>
@@ -81686,6 +81714,13 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="7" label="Fail (updates disabled)"/>
 </enum>
 
+<enum name="ContentSuggestionsUIUpdateResult2" type="int">
+  <int value="0" label="Success (appended)"/>
+  <int value="1" label="Success (some suggestions replaced)"/>
+  <int value="6" label="Fail (all suggestions seen)"/>
+  <int value="7" label="Fail (updates disabled)"/>
+</enum>
+
 <enum name="ContentType" type="int">
   <int value="-1" label="Invalid setting"/>
   <int value="0" label="Cookies setting"/>