Log suggestion scores in 10 discrete buckets.

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 8a133ee1a9f3079e510354276b699b4701a5ce6e..5bc363fb1d0dd656408bfaa64a38acc6df71136e 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -38784,6 +38784,9 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 </histogram>
 
 <histogram name="NewTabPage.ContentSuggestions.MenuOpenedScore" units="score">
+  <obsolete>
+    Replaced by NewTabPage.ContentSuggestions.MenuOpenedScoreNormalized.
+  </obsolete>
   <owner>treib@chromium.org</owner>
   <summary>
     Android: The relevance score of a suggestion card on the NTP whose
@@ -38792,6 +38795,20 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="NewTabPage.ContentSuggestions.MenuOpenedScoreNormalized"
+    units="score">
+  <owner>tschumann@chromium.org</owner>
+  <summary>
+    Android: The relevance score of a suggestion card on the NTP whose
+    long-press menu was opened, analogous to
+    NewTabPage.ContentSuggestions.OpenedScoreNormalized. Scores (which are
+    typically floats within (0,1]) get reported as discrete integers within
+    [1,10]. For instance, the discrete value 1 represents score values from
+    (0.0, 0.1]. The discrete value 11 is the overflow bucket for unexpectedly
+    high scores.
+  </summary>
+</histogram>
+
 <histogram name="NewTabPage.ContentSuggestions.MoreButtonClicked" units="index">
   <owner>treib@chromium.org</owner>
   <summary>
@@ -38847,6 +38864,9 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 </histogram>
 
 <histogram name="NewTabPage.ContentSuggestions.OpenedScore" units="score">
+  <obsolete>
+    Replaced by NewTabPage.ContentSuggestions.OpenedScoreNormalized.
+  </obsolete>
   <owner>treib@chromium.org</owner>
   <summary>
     Android: The score of a suggestion card on the NTP that is clicked through
@@ -38855,6 +38875,20 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="NewTabPage.ContentSuggestions.OpenedScoreNormalized"
+    units="score">
+  <owner>tschumann@chromium.org</owner>
+  <summary>
+    Android: The score of a suggestion card on the NTP that is clicked through
+    to the host website of the content. The recorded score is from the moment
+    the suggestion was fetched, it could have changed since. Scores (which are
+    typically floats within (0,1]) get reported as discrete integers within
+    [1,10]. For instance, the discrete value 1 represents score values from
+    (0.0, 0.1]. The discrete value 11 is the overflow bucket for unexpectedly
+    high scores.
+  </summary>
+</histogram>
+
 <histogram name="NewTabPage.ContentSuggestions.Shown" units="index">
   <owner>treib@chromium.org</owner>
   <summary>
@@ -38877,6 +38911,9 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 </histogram>
 
 <histogram name="NewTabPage.ContentSuggestions.ShownScore" units="score">
+  <obsolete>
+    Replaced by NewTabPage.ContentSuggestions.ShownScoreNormalized.
+  </obsolete>
   <owner>treib@chromium.org</owner>
   <summary>
     Android: The score of a suggestion card that was shown on the NTP. A card is
@@ -38885,6 +38922,20 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="NewTabPage.ContentSuggestions.ShownScoreNormalized"
+    units="score">
+  <owner>tschumann@chromium.org</owner>
+  <summary>
+    Android: The score of a suggestion card that was shown on the NTP. A card is
+    considered shown when at least 1/3 of its height is visible on the screen.
+    For each card, at most one impression is recorded per NTP instance. Scores
+    (which are typically floats within (0,1]) get reported as discrete integers
+    within [1,10]. For instance, the discrete value 1 represents score values
+    from (0.0, 0.1]. The discrete value 11 is the overflow bucket for
+    unexpectedly high scores.
+  </summary>
+</histogram>
+
 <histogram name="NewTabPage.ContentSuggestions.TimeSinceLastBackgroundFetch"
     units="ms">
   <owner>markusheintz@chromium.org</owner>
@@ -109719,15 +109770,21 @@ value.
   <affected-histogram name="NewTabPage.ContentSuggestions.MenuOpened"/>
   <affected-histogram name="NewTabPage.ContentSuggestions.MenuOpenedAge"/>
   <affected-histogram name="NewTabPage.ContentSuggestions.MenuOpenedScore"/>
+  <affected-histogram
+      name="NewTabPage.ContentSuggestions.MenuOpenedScoreNormalized"/>
   <affected-histogram name="NewTabPage.ContentSuggestions.MoreButtonClicked"/>
   <affected-histogram name="NewTabPage.ContentSuggestions.MoreButtonShown"/>
   <affected-histogram name="NewTabPage.ContentSuggestions.OpenDisposition"/>
   <affected-histogram name="NewTabPage.ContentSuggestions.Opened"/>
   <affected-histogram name="NewTabPage.ContentSuggestions.OpenedAge"/>
   <affected-histogram name="NewTabPage.ContentSuggestions.OpenedScore"/>
+  <affected-histogram
+      name="NewTabPage.ContentSuggestions.OpenedScoreNormalized"/>
   <affected-histogram name="NewTabPage.ContentSuggestions.Shown"/>
   <affected-histogram name="NewTabPage.ContentSuggestions.ShownAge"/>
   <affected-histogram name="NewTabPage.ContentSuggestions.ShownScore"/>
+  <affected-histogram
+      name="NewTabPage.ContentSuggestions.ShownScoreNormalized"/>
   <affected-histogram name="NewTabPage.ContentSuggestions.VisitDuration"/>
 </histogram_suffixes>