📰 Use first seen position in suggestion UMA

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 a1dbc2bceda5834bea7a6dfdbc7039f4f71b9ed1..0d782d2f6385c708d0eb26838b78b6e9a8497850 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -39036,10 +39036,10 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <summary>
     Android: The position of a suggestion card on the NTP that is dismissed,
     typically by swiping it away. The suggestion had a URL that was NOT visited
-    before. We track the position the suggestion had in the list when the NTP
-    was loaded. This tracked position can be different from the position
+    before. We track the position the card had in the list when it was first
+    seen by the user. This tracked position can be different from the position
     observed by the user, e.g. when the user dismissed some suggestions from the
-    list before.
+    list or requested more that got inserted in the middle of the feed.
   </summary>
 </histogram>
 
@@ -39048,10 +39048,10 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <summary>
     Android: The position of a suggestion card on the NTP that is dismissed,
     typically by swiping it away. The suggestion had a URL that was visited
-    before. We track the position the suggestion had in the list when the NTP
-    was loaded. This tracked position can be different from the position
+    before. We track the position the card had in the list when it was first
+    seen by the user. This tracked position can be different from the position
     observed by the user, e.g. when the user dismissed some suggestions from the
-    list before.
+    list or requested more that got inserted in the middle of the feed.
   </summary>
 </histogram>
 
@@ -39103,9 +39103,10 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
     Android: The position of a &quot;More&quot; suggestion card that was clicked
     on the NTP. A card is considered shown when at least 1/3 of its height is
     visible on the screen. We track the position the card had in the list when
-    the NTP was loaded. This tracked position can be different from the position
-    observed by the user, e.g. when the user dismissed some suggestions from the
-    list.
+    it was first seen by the user. This tracked position can be different from
+    the position observed by the user, e.g. when the user dismissed some
+    suggestions from the list or requested more that got inserted in the middle
+    of the feed.
   </summary>
 </histogram>
 
@@ -39115,10 +39116,10 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
     Android: The position of a &quot;More&quot; 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. We track the position the card had in the list when the NTP
-    was loaded. This tracked position can be different from the position
-    observed by the user, e.g. when the user dismissed some suggestions from the
-    list.
+    NTP instance. We track the position the card had in the list when it was
+    first seen by the user. This tracked position can be different from the
+    position observed by the user, e.g. when the user dismissed some suggestions
+    from the list or requested more that got inserted in the middle of the feed.
   </summary>
 </histogram>
 
@@ -39164,11 +39165,12 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 <histogram name="NewTabPage.ContentSuggestions.Opened" units="index">
   <owner>treib@chromium.org</owner>
   <summary>
-    Android: The position of a suggestion card on the NTP that is clicked
-    through to the host website of the content. We track the position the
-    suggestion had in the list when the NTP was loaded. This tracked position
+    Android: The position of the suggestion card on the NTP, that is clicked
+    through to the host website of the content. We track the position the card
+    had in the list when it was first seen by the user. This tracked position
     can be different from the position observed by the user, e.g. when the user
-    dismissed some suggestions from the list.
+    dismissed some suggestions from the list or requested more that got inserted
+    in the middle of the feed.
   </summary>
 </histogram>
 
@@ -39188,8 +39190,8 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
     Android: The index of a category on the NTP, whose suggestion card is
     clicked through to the host website of the content. This tracked index can
     be different from the position observed by the user, e.g. for the user a
-    category may be at the top of the NTP, but with index 1, because there is an
-    empty category above (with index 0).
+    category may be at the top of the NTP, but with index 1, because they
+    dismissed the one that was previously at the top.
   </summary>
 </histogram>
 
@@ -39225,9 +39227,10 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
     Android: The position 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.
-    We track the position the suggestion had in the list when the NTP was
-    loaded. This tracked position can be different from the position observed by
-    the user, e.g. when the user dismissed some suggestions from the list.
+    We track the position the card had in the list when it was first seen by the
+    user. This tracked position can be different from the position observed by
+    the user, e.g. when the user dismissed some suggestions from the list or
+    requested more that got inserted in the middle of the feed.
   </summary>
 </histogram>