[rb] put encoded profile back into 'zip' for ProfileHelper#as_json

this is for serialization, the base64 string is always extracted before sending over the wire

Author: lmtierney

rb/lib/selenium/webdriver/common/profile_helper.rb

@@ -30,7 +30,7 @@ def self.included(base)
       end
 
       def as_json(*)
-        Zipper.zip(layout_on_disk)
+        {zip: Zipper.zip(layout_on_disk)}
       end
 
       def to_json(*)
@@ -61,7 +61,7 @@ def verify_model(model)
 
       module ClassMethods
         def from_json(json)
-          data = JSON.parse(json)
+          data = JSON.parse(json).fetch('zip')
 
           # can't use Tempfile here since it doesn't support File::BINARY mode on 1.8
           # can't use Dir.mktmpdir(&blk) because of http://jira.codehaus.org/browse/JRUBY-4082