gistfile1.js

my.Base = function(drawEventType) {
  if (TRACING_ENABLED) {
    this.drawEventType_ = drawEventType;
  }
};

my.Base.prototype.draw = function() {
  var scope = TRACING_ENABLED ? this.drawEventType_() : null;
  ...
  leaveScope(scope);
};

my.Subclass = function() {
  goog.base(my.Subclass.DRAW_EVENT_TYPE);
};

my.Subclass.DRAW_EVENT_TYPE = createScopeEvent('my.Subclass#draw');