Provide Copy button for username in password settings

ios/chrome/app/strings/ios_strings.grd

 <?xml version="1.0" encoding="UTF-8"?>
 
 <!--
 This file contains definition of resources that will be translated for each
 locale.  The strings in this file are specific to iOS.
 -->
 
 <grit base_dir="." latest_public_release="0" current_release="1"
       output_all_resource_defines="false" source_lang_id="en" enc_check="möl">
   <outputs>
@@ skipping 1089 matching lines @@
       </message>
       <message name="IDS_IOS_SAVE_PASSWORDS_MANAGE_ACCOUNT" desc="Header text with link for the view in Settings for managing saved passwords. [Length: unlimited] [iOS only]">
         View and manage saved passwords at <ph name="BEGIN_LINK">BEGIN_LINK</ph>passwords.google.com<ph name="END_LINK">END_LINK</ph>
       </message>
       <message name="IDS_IOS_SEARCH_COPIED" desc="The message displayed when the search is copied via long press (contextual search) [Length: 10em] [iOS only]">
         Copied
       </message>
       <message name="IDS_IOS_SEARCH_ENGINE_SETTING_TITLE" desc="The title for Search Engine selection setting [iOS only]">
         Search Engine
       </message>
+      <message name="IDS_IOS_SETTINGS_USERNAME_COPY_BUTTON" desc="Button that the user can press to copy the username to clipboard. [Length: 12em]">
+        Copy
+      </message>
       <message name="IDS_IOS_SETTINGS_PASSWORD_COPY_BUTTON" desc="Button that the user can press to copy the password to clipboard. [Length: 12em]">
         Copy
       </message>
       <message name="IDS_IOS_SETTINGS_PASSWORD_DELETE_BUTTON" desc="Button that the user can press to delete the saved password. [Length: 31em]">
         Delete Saved Password
       </message>
       <message name="IDS_IOS_SETTINGS_PASSWORD_HIDDEN_LABEL" desc="Accessibility label stating that the element is displaying a hidden password.">
         Hidden, Password
       </message>
       <message name="IDS_IOS_SETTINGS_PASSWORD_HIDE_BUTTON" desc="Button that the user can press to change the way the password is displayed from plain text to obscured form (i.e. from plain text to dots). [Length: 12em]">
         Hide
       </message>
       <message name="IDS_IOS_SETTINGS_PASSWORD_REAUTH_REASON_COPY" desc="Message explaining that the reason why we are requiring the user to re-authenticate is to be able to copy the password. This is shown by iOS in the Touch ID reauthentication system dialogue, right under the OS string 'Touch ID for $BROWSER_NAME'. [Length: 22em]">
         Copy password
       </message>
       <message name="IDS_IOS_SETTINGS_PASSWORD_REAUTH_REASON_SHOW" desc="Message explaining that the reason why we are requiring the user to re-authenticate is to be able to show the password in plain text. This is shown by iOS in the Touch ID reauthentication system dialogue, right under the OS string 'Touch ID for $BROWSER_NAME'. [Length: 22em]">
         Show password
       </message>
       <message name="IDS_IOS_SETTINGS_PASSWORD_SHOW_BUTTON" desc="Button that the user can press in order to have the password displayed in plain text. [Length: 12em]">
         Show
       </message>
+      <message name="IDS_IOS_SETTINGS_USERNAME_WAS_COPIED_MESSAGE" desc="Confirmation that the username was copied. This is shown alone in an infobar at the bottom of the screen. [Length: 40em]">
+        Your username was copied.
+      </message>
       <message name="IDS_IOS_SETTINGS_PASSWORD_WAS_COPIED_MESSAGE" desc="Confirmation that the password was copied. This is shown alone in an infobar at the bottom of the screen after the user successfully reauthenticates with Touch ID or PIN. [Length: 40em]">
         Your password was copied.
       </message>
       <message name="IDS_IOS_SETTINGS_PASSWORD_WAS_NOT_COPIED_MESSAGE" desc="Message informing the user that the password was not copied because the authentication failed. This is shown alone in an infobar at the bottom of the screen after the user tries to reauthenticate with Touch ID or PIN to copy the password and fails. [Length: 53em]">
         Authentication failed. Your password was not copied.
       </message>
       <message name="IDS_IOS_SETTINGS_TITLE" desc="Title for the settings panel [iOS].">
         Settings
       </message>
       <message name="IDS_IOS_SETTING_OFF" desc="Generic status label displayed in Settings to show that a setting is currently turned off. [Length: 5em] [iOS only]">
@@ skipping 356 matching lines @@
       </message>
       <message name="IDS_IOS_SIGNIN_PROMO_CONTINUE_AS" desc="Button that the user can press to login without asking the password and continue using Chrome with this acccount. [Length: 9em]">
         Continue as <ph name="NAME">$1<ex>John Doe</ex></ph>
       </message>
       <message name="IDS_IOS_SIGNIN_PROMO_NOT" desc="Button that the user can press if they are not the profile that Chrome found (opposite of 'Continue as Joe Doe').">
         Not <ph name="EMAIL">$1<ex>john.doe@example.com</ex>?</ph>
       </message>
     </messages>
   </release>
 </grit>