Debug: parameterize 'step over' action with a frame where the step must be performed

R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/23533015

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16581 ce2b1a6d-e550-0410-aec6-3dcde31c8c00