Adding accessibility to the close button in sign-in promo

ios/chrome/app/strings/ios_strings.grd

Index: ios/chrome/app/strings/ios_strings.grd
diff --git a/ios/chrome/app/strings/ios_strings.grd b/ios/chrome/app/strings/ios_strings.grd
index 3139afcff2850e47d9738c6f28ad2e366db531a6..2ed90037d00bc3d522fed4271a7efb05c174e3d9 100644
--- a/ios/chrome/app/strings/ios_strings.grd
+++ b/ios/chrome/app/strings/ios_strings.grd
@@ -1513,6 +1513,9 @@ Your data was encrypted with your sync passphrase on <ph name="TIME">$2<ex>Sept
       <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>
+      <message name="IDS_IOS_SIGNIN_PROMO_CLOSE_ACCESSIBILITY" desc="Accessibility label to describ the close button in the sign-in promo element">

[lpromero, 2017/05/23 12:06:16]

Nit: add a period at the end of the description sentence.

[lpromero, 2017/05/23 12:06:16]

*describe

[jlebel, 2017/05/23 12:43:25]

Done.

+        Close
+      </message>
       <message name="IDS_IOS_SYSTEM_MAIL_APP" desc="Name of iOS system-provided Mail app. Note that this is not consistently translated for all locales, e.g. it is still 'Mail' (in English) for French locale, but is translated to '邮件' for Chinese locale. [Length: 10em]">
         Mail
       </message>