[TTS] Add some initial signals for Tap in content.

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 d76c6f8ffa5d9a8ceeccc93c9f82f20bb210a9e1..630f6de62e3ac428a549013728f1d542da4ec14e 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -65014,6 +65014,16 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Search.ContextualSearchLongWordSeen"
+    enum="ContextualSearchResultsSeen">
+  <owner>donnd@chromium.org</owner>
+  <owner>twellington@chromium.org</owner>
+  <summary>
+    Whether results were seen for a Tap that was on a word considered
+    &quot;long&quot;. Recorded when the UX is hidden. Implemented for Android.
+  </summary>
+</histogram>
+
 <histogram name="Search.ContextualSearchLowPrioritySearchRequestStatus"
     enum="ContextualSearchSearchRequestStatus">
   <owner>donnd@chromium.org</owner>
@@ -65045,6 +65055,17 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Search.ContextualSearchNotNearWordEdgeSeen"
+    enum="ContextualSearchResultsSeen">
+  <owner>donnd@chromium.org</owner>
+  <owner>twellington@chromium.org</owner>
+  <summary>
+    Whether results were seen for a Tap that was not considered near the edge of
+    a word or in a very short word. Recorded when the UX is hidden. Implemented
+    for Android.
+  </summary>
+</histogram>
+
 <histogram name="Search.ContextualSearchPanelOpenDuration" units="ms">
   <owner>donnd@chromium.org</owner>
   <owner>twellington@chromium.org</owner>
@@ -65456,6 +65477,16 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Search.ContextualSearchShortWordSeen"
+    enum="ContextualSearchResultsSeen">
+  <owner>donnd@chromium.org</owner>
+  <owner>twellington@chromium.org</owner>
+  <summary>
+    Whether results were seen for a Tap that was on a word considered
+    &quot;short&quot;. Recorded when the UX is hidden. Implemented for Android.
+  </summary>
+</histogram>
+
 <histogram name="Search.ContextualSearchShouldTranslate"
     enum="ContextualSearchShouldTranslate">
   <owner>donnd@chromium.org</owner>