The SmiOperation function was not used anymore. Remove it and rename VirtualFrameSmiOperation to SmiOperation.
Review URL: http://codereview.chromium.org/1723021

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4548 ce2b1a6d-e550-0410-aec6-3dcde31c8c00