Animate IOS Share extension button.

ios/chrome/share_extension/strings/ios_share_extension_strings.grd

Index: ios/chrome/share_extension/strings/ios_share_extension_strings.grd
diff --git a/ios/chrome/share_extension/strings/ios_share_extension_strings.grd b/ios/chrome/share_extension/strings/ios_share_extension_strings.grd
index fd8dd3841a7f44de23dfaab8e50a0b8a607cda6c..a99a7dd0426ad0b7b61fee0a50fb4b5b1c4cc057 100644
--- a/ios/chrome/share_extension/strings/ios_share_extension_strings.grd
+++ b/ios/chrome/share_extension/strings/ios_share_extension_strings.grd
@@ -136,6 +136,9 @@ all other OS specific variables will be false.
       <message name="IDS_IOS_ADD_BOOKMARKS_SHARE_EXTENSION" desc="Share extension button to add to bookmarks [Length: 30em]" meaning="Button title [Length: 30em]">
         Add to Bookmarks 
       </message>
+      <message name="IDS_IOS_ADDED_ITEM_SHARE_EXTENSION" desc="Label of the button 'add to' after it has been pressed confirming the action to the user.">
+        Added
+      </message>
       <message name="IDS_IOS_ERROR_MESSAGE_SHARE_EXTENSION" desc="Share extension message to tell the user the URL cannot be processed. The name of the application will be put in place of APPLICATION_NAME">
         APPLICATION_NAME cannot handle this link.
       </message>