As long as all debugger messages are handled by a single static method we need a way to identify request sender to route the response to the right handler. To accomplish this clients can send some additional data along with command text and debugger will later pass this data to the message handler along with the response text.

Review URL: http://codereview.chromium.org/67266

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1755 ce2b1a6d-e550-0410-aec6-3dcde31c8c00