[ios] Fixes Password Messages metrics.

TBR=sczs@chromium.org

(cherry picked from commit a20f627720fc7807bca766dba8dda0e258bf0f55)

Bug: 974364
Change-Id: I985bbe45fbef1c6ab91e65a5c554e05eef17c3a7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1660804
Reviewed-by: Vasilii Sukhanov <vasilii@chromium.org>
Commit-Queue: Sergio Collazos <sczs@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#669691}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1664653
Reviewed-by: Sergio Collazos <sczs@chromium.org>
Cr-Commit-Position: refs/branch-heads/3809@{#414}
Cr-Branched-From: d82dec1a818f378c464ba307ddd9c92133eac355-refs/heads/master@{#665002}

diff --git a/ios/chrome/browser/passwords/ios_chrome_password_infobar_metrics_recorder.h b/ios/chrome/browser/passwords/ios_chrome_password_infobar_metrics_recorder.h
index ff02acb9..ad13f58 100644
--- a/ios/chrome/browser/passwords/ios_chrome_password_infobar_metrics_recorder.h
+++ b/ios/chrome/browser/passwords/ios_chrome_password_infobar_metrics_recorder.h

@@ -21,13 +21,15 @@
 // values should never be reused.
 enum class MobileMessagesPasswordsModalEvent {
   // PasswordInfobar username was edited.
-  EditedUserName = 1,
+  EditedUserName = 0,
   // PasswordInfobar password was edited.
-  EditedPassword = 2,
+  EditedPassword = 1,
   // PasswordInfobar password was unmasked.
-  UnmaskedPassword = 3,
+  UnmaskedPassword = 2,
+  // PasswordInfobar password was masked.
+  MaskedPassword = 3,
   // Highest enumerator. Recommended by Histogram metrics best practices.
-  kMaxValue = UnmaskedPassword,
+  kMaxValue = MaskedPassword,
 };
 
 // Values for the UMA Mobile.Messages.Passwords.Modal.Dismiss histogram. These

diff --git a/ios/chrome/browser/ui/infobars/modals/infobar_password_table_view_controller.mm b/ios/chrome/browser/ui/infobars/modals/infobar_password_table_view_controller.mm
index fbbe081..d2728cc 100644
--- a/ios/chrome/browser/ui/infobars/modals/infobar_password_table_view_controller.mm
+++ b/ios/chrome/browser/ui/infobars/modals/infobar_password_table_view_controller.mm

@@ -351,6 +351,8 @@
     self.passwordItem.identifyingIconAccessibilityLabel =
         l10n_util::GetNSString(
             IDS_IOS_INFOBAR_MODAL_PASSWORD_REVEAL_PASSWORD_HINT);
+    [self.passwordMetricsRecorder
+        recordModalEvent:MobileMessagesPasswordsModalEvent::MaskedPassword];
   } else {
     self.passwordItem.identifyingIcon =
         [UIImage imageNamed:@"infobar_hide_password_icon"];
@@ -358,6 +360,8 @@
     self.passwordItem.identifyingIconAccessibilityLabel =
         l10n_util::GetNSString(
             IDS_IOS_INFOBAR_MODAL_PASSWORD_HIDE_PASSWORD_HINT);
+    [self.passwordMetricsRecorder
+        recordModalEvent:MobileMessagesPasswordsModalEvent::UnmaskedPassword];
   }
   [self reconfigureCellsForItems:@[ self.passwordItem ]];
 }

diff --git a/tools/metrics/histograms/enums.xml b/tools/metrics/histograms/enums.xml
index 257139d..6c577fb 100644
--- a/tools/metrics/histograms/enums.xml
+++ b/tools/metrics/histograms/enums.xml

@@ -38711,6 +38711,7 @@
   <int value="0" label="EditedUserName"/>
   <int value="1" label="EditedPassword"/>
   <int value="2" label="UnmaskedPassword"/>
+  <int value="3" label="MaskedPassword"/>
 </enum>
 
 <enum name="MobileMessagesPasswordsModalPresent">