This adds access to the LiveEdit API object, frame.restart(), and
various breakpoint setters. The LiveEdit API still depends on the JS
debugging context and blocks its removal; but it should be removed
once LiveEdit is rewritten in the midterm.

BUG=v8:5530

Review-Url: https://codereview.chromium.org/2503293002
Cr-Commit-Position: refs/heads/master@{#41062}