Mangle names of function parameters.

[karlklose]

Parameter names are not mangled and can conflict with source identifiers.

Dart:
void show(final String t0) {
  assert (null !== t0 && 0 !== t0.length);
  document.query('#status').innerHTML = t0;
}

is compiled to:
$.show = function(t0) {
  var t0 = !((void 0) === t0);
  if (t0) {
    var t1 = !(0 === $.get$length(t0));
  } else {
    t1 = t0;
  }
  $.assert(t1);
  $.document().query$1('#status').set$innerHTML(t0);
};

[kasperl]

Set owner to ngeoffray@google.com.
Removed Priority-Medium label.
Added Priority-High label.

[DartBot]

This comment was originally written by ngeoffray@google.com

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Fixed in https://chromiumcodereview.appspot.com/10543050/.

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Added Fixed label.