Settings Rewrite: Add Sign-in (Chrome) section

chrome/app/settings_strings.grdp

 <?xml version="1.0" encoding="utf-8"?>
 <!-- Settings-specific strings (included from generated_resources.grd). -->
 <grit-part>
   <!-- Policy Indicators -->
   <message name="IDS_SETTINGS_CONTROLLED_SETTING_EXTENSION" desc="Text displayed in the controlled settings indicator tooltip when a setting's value is enforced by an extension.">
     This setting is controlled by extension <ph name="NAME">$1<ex>Settings Extension</ex></ph> 
   </message>
 
   <if expr="chromeos">
     <!-- Accessibility Page -->
@@ skipping 430 matching lines @@
   <message name="IDS_SETTINGS_SITE_SETTINGS_EXCEPTIONS" desc="Label for exception sites in site settings.">
     Exceptions
   </message>
   <message name="IDS_SETTINGS_SITE_SETTINGS_ADD_SITE" desc="Label for add site button in site settings.">
     Add Site
   </message>
   <message name="IDS_SETTINGS_SITE_SETTINGS_SITE_URL" desc="Label for site URL text entry in site settings.">
     Site URL
   </message>
 
+  <!-- Sign in Page -->

[michaelpg, 2015/10/03 05:23:32]

ubernit: Sign-in (hyphenate prepositional verbs used as modifiers, but not
prepositional verbs used as verbs)

rationale: using correct English in comments makes incorrect English less likely
to slip into user-visible strings

[tommycli, 2015/10/05 17:15:45]

good call  :D

+  <message name="IDS_SETTINGS_SIGNIN" desc="Name of the settings page which manages Chrome's signed-in Google profile.">
+    Sign in
+  </message>
+
   <!-- Sync Page -->
   <message name="IDS_SETTINGS_SYNC" desc="Name of the settings page which manages syncing data between multiple browser instances with the same Google profile.">
     Advanced sync settings
   </message>
   <message name="IDS_SETTINGS_SYNC_EVERYTHING_MENU_OPTION" desc="Name of the menu option which, when selected, causes all properties to be synced.">
     Sync everything
   </message>
   <message name="IDS_SETTINGS_CHOOSE_WHAT_TO_SYNC_MENU_OPTION" desc="Name of the menu option which, when selected, allows the user to select a subset of properties to be synced.">
     Choose what to sync
   </message>
@@ skipping 65 matching lines @@
   <message name="IDS_SETTINGS_USERS_SHOW_ON_SIGNIN_LABEL" desc="Label for the 'show users on sign-in screen' setting.">
     Show usernames and photos on the sign-in screen
   </message>
   <message name="IDS_SETTINGS_USERS_RESTRICT_SIGNIN_LABEL" desc="Label for the setting for restricting sign in to specific users.">
     Restrict sign-in to the following users:
   </message>
   <message name="IDS_SETTINGS_USERS_ADD_USERS_LABEL" desc="Label for the input field for adding users.">
     Add users
   </message>
 </grit-part>