Collect data on site engagement vs dialogs.

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 ccb015218961048b5dfb1b1cfa73160813bd231d..d4973e99c7f7d67f5bb764531e23f23b755f5c75 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -20645,6 +20645,40 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="JSDialogs.CountOfJSDialogMessageCharactersKarmaHigher">
+  <owner>avi@chromium.org</owner>
+  <summary>
+    The count of the number of characters in JavaScript dialog messages shown by
+    a page that has a site engagement level of &quot;medium&quot; through
+    &quot;max&quot;.
+  </summary>
+</histogram>
+
+<histogram name="JSDialogs.CountOfJSDialogMessageCharactersKarmaLow">
+  <owner>avi@chromium.org</owner>
+  <summary>
+    The count of the number of characters in JavaScript dialog messages shown by
+    a page that has a site engagement level of &quot;low&quot;.
+  </summary>
+</histogram>
+
+<histogram name="JSDialogs.CountOfJSDialogMessageCharactersKarmaNone">
+  <owner>avi@chromium.org</owner>
+  <summary>
+    The count of the number of characters in JavaScript dialog messages shown by
+    a page that has a site engagement level of &quot;none&quot;.
+  </summary>
+</histogram>
+
+<histogram name="JSDialogs.CountOfJSDialogMessageCharactersUserSuppressed">
+  <owner>avi@chromium.org</owner>
+  <summary>
+    The count of the number of characters in JavaScript dialog messages that
+    were suppressed by the user. Compare with
+    JSDialogs.CountOfJSDialogMessageCharacters.
+  </summary>
+</histogram>
+
 <histogram name="JSDialogs.CountOfJSDialogMessageNewlines">
   <owner>avi@chromium.org</owner>
   <summary>
@@ -20712,6 +20746,11 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="JSDialogs.SiteKarmaOfDialogs">
+  <owner>avi@chromium.org</owner>
+  <summary>The site engagement values of sites showing dialogs.</summary>
+</histogram>
+
 <histogram name="Keyboard.KeystrokeDeltas" units="ms">
   <obsolete>
     Deprecated 07/2016 in crbug.com/631204 with KeyboardUmaEventFilter removal.