Add histograms for notices about other forms of browsing history

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 e664233b9a207d94e4df98e0fd97f8c63bebf693..7c71a576f950dc0293d297c06dd9d1536cbd568f 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -16768,6 +16768,17 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 </histogram>
 
 <histogram
+    name="History.ClearBrowsingData.HistoryNoticeShownInFooterWhenUpdated"
+    enum="BooleanShown">
+  <owner>msramek@chromium.org</owner>
+  <summary>
+    Whether a notice about other forms of browsing history was shown in the
+    footer of the Clear Browsing Data dialog. This is recorded every time the
+    dialog is opened.
+  </summary>
+</histogram>
+
+<histogram
     name="History.ClearBrowsingData.PasswordsDeletion.AdditionalDatatypesCount">
   <owner>msramek@chromium.org</owner>
   <summary>
@@ -16776,6 +16787,15 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="History.ClearBrowsingData.ShownHistoryNoticeAfterClearing"
+    enum="BooleanShown">
+  <owner>msramek@chromium.org</owner>
+  <summary>
+    Whether a dialog with a notice about other forms of browsing history was
+    shown after the user deleted data from the Clear Browsing Data dialog.
+  </summary>
+</histogram>
+
 <histogram name="History.ClearBrowsingData.UserDeletedCookieOrCache"
     enum="CookieOrCacheDeletion">
   <owner>msramek@chromium.org</owner>
@@ -17110,6 +17130,16 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="History.ShownHeaderAboutOtherFormsOfBrowsingHistory"
+    enum="BooleanShown">
+  <owner>msramek@chromium.org</owner>
+  <summary>
+    Whether the notice about other forms of browsing history was shown in the
+    header of the History page when the header was displayed. The header is
+    refreshed with every history query.
+  </summary>
+</histogram>
+
 <histogram name="History.TopHostsVisitsByRank" units="rank">
   <owner>twifkak@chromium.org</owner>
   <owner>bengr@chromium.org</owner>