Fix indentation of javascript statements under multi-line statement block.

Let me know your opinion on this fix.

https://groups.google.com/forum/#!topic/codemirror/wXQm2H0ACyA/discussion

myproj.blah.blah.enterDocument =
    function() { <== 4-space multi-line statement block.
  goog.base(this, 'enterDocument'); // <== expected 2-space indentation.
      goog.base(this, 'enterDocument'); // <== actual/incorrect 6-space indentation.