Mirror object for scope of frame or function. Either frame or function must
be specified.
@param {FrameMirror} frame The frame this scope is a part of
@param {FunctionMirror} function The function this scope is a part of
@param {number} index The scope index in the frame
@param {Array=} opt_details Raw scope details data
@constructor
@extends Mirror
function ScopeMirror(frame, fun, index, opt_details) {
  %_Call(Mirror, this, MirrorType.SCOPE_TYPE);
  if (frame) {
    this.frame_index_ = frame.index_;
  } else {
    this.frame_index_ = UNDEFINED;
  }
  this.scope_index_ = index;
  this.details_ = new ScopeDetails(frame, fun, index, opt_details);
}