Prolong PasswordManager.AccountChooserDialog histograms.

Fixed: 1144810
Change-Id: Id1ab4f2860d7b6a0f68ddd1309d46619162a34dd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2521530Reviewed-by: Caitlin Fischer <caitlinfischer@google.com>
Reviewed-by: Ilya Sherman <isherman@chromium.org>
Commit-Queue: Vasilii Sukhanov <vasilii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#825785}

tools/metrics/histograms/histograms_xml/password/histograms.xml

@@ -176,20 +176,22 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="PasswordManager.AccountChooserDialogMultipleAccounts"
-    enum="AccountChooserDismissalReason" expires_after="2020-12-12">
+    enum="AccountChooserDismissalReason" expires_after="2021-06-01">
   <owner>vasilii@chromium.org</owner>
   <owner>jdoerrie@chromium.org</owner>
   <summary>
-    The dismissal reason of the account chooser with multiple accounts.
+    The dismissal reason of the account chooser with multiple accounts. Recorded
+    when the account chooser is dismissed.
   </summary>
 </histogram>
 
 <histogram name="PasswordManager.AccountChooserDialogOneAccount"
-    enum="AccountChooserDismissalReason" expires_after="2020-12-12">
+    enum="AccountChooserDismissalReason" expires_after="2021-06-01">
   <owner>vasilii@chromium.org</owner>
   <owner>jdoerrie@chromium.org</owner>
   <summary>
-    The dismissal reason of the account chooser with one account.
+    The dismissal reason of the account chooser with one account. Recorded when
+    the account chooser is dismissed.
   </summary>
 </histogram>