Update frame around SAML IdP pages to new GAIA style

chrome/app/chromeos_strings.grdp

 <?xml version="1.0" encoding="utf-8"?>
 <!-- ChromeOS-specific strings (included from generated_resources.grd).
      Everything in this file is wrapped in <if expr="chromeos">. -->
 <grit-part>
   <message name="IDS_EMPTY_STRING" desc="Empty string, exist only to make code generic. No translation required.">
   </message>
   <message name="IDS_CHROMEBOOK" desc="The localized name for Chromebook.">
     Chromebook
   </message>
   <message name="IDS_CHROMEBOX" desc="The localized name for Chromebox">
@@ skipping 1548 matching lines @@
   <message name="IDS_LOGIN_PASSWORD_CHANGED_MIGRATE" desc="Migrate option of the password changed dialog">
     Migrate all Chrome OS data to the new password
 (requires previous password)
   </message>
   <message name="IDS_LOGIN_PREVIOUS_PASSWORD" desc="Password field text on the password changed dialog">
     Previous password
   </message>
   <message name="IDS_LOGIN_SAML_NOTICE" desc="Text message displayed above SAML portal to early indicate that the user is being redirected to another sign-in provider.">
     The sign-in service below is hosted by <ph name="SAML_DOMAIN">$1<ex>saml.com</ex></ph>. Sign in to continue.
   </message>
+  <message name="IDS_LOGIN_SAML_NOTICE_NEW_GAIA_FLOW" desc="Text message displayed above SAML portal to early indicate that the user is being redirected to another sign-in provider. This is the version of the string used in the new GAIA flow.">
+    This sign-in service is hosted by <ph name="SAML_DOMAIN">$1<ex>saml.com</ex></ph>.
+  </message>
   <message name="IDS_LOGIN_CONFIRM_PASSWORD_TITLE" desc="Title for the confirm password dialog.">
     Complete sign-in
   </message>
   <message name="IDS_LOGIN_CONFIRM_PASSWORD_LABEL" desc="Label for the password field on the confirm password dialog.">
     Please re-enter your password
   </message>
   <message name="IDS_LOGIN_CONFIRM_PASSWORD_CONFIRM_BUTTON" desc="Label for the confirm button on the confirm password dialog.">
     Confirm
   </message>
   <message name="IDS_LOGIN_CONFIRM_PASSWORD_TEXT" desc="Text to explain to user why password needs to be typed again in the confirm password UI.">
@@ skipping 4695 matching lines @@
     Enable MTP write support in file manager. Some operations (editing an image on MTP volume) are not supported yet.
   </message>
   <message name="IDS_FILE_SYSTEM_REQUEST_FILE_SYSTEM_NOTIFICATION_MESSAGE" desc="Message in a notification about granted read-only pemissions (read, write, delete, create files and directories) to a volume (eg. USB drive, SD card, MTP device) with the specified name to the extension.">
     Read-only access to <ph name="VOLUME_NAME">$1<ex>FooBar 4GB</ex></ph> has been granted.
   </message>
   <message name="IDS_FILE_SYSTEM_REQUEST_FILE_SYSTEM_NOTIFICATION_WRITABLE_MESSAGE" desc="Message in a notification about granted full permissions (read, write, delete, create files and directories) to a volume (eg. USB drive, SD card, MTP device) with the specified name to the extension.">
     Read and write access to <ph name="VOLUME_NAME">$1<ex>FooBar 4GB</ex></ph> has been granted.
   </message>
 
 </grit-part>