processTaskResults = function(label, taskResults) {
    allResults[label] = taskResults;
    if (goog.isFunction(displayResultsFun)) {
      displayResultsFun(label, taskResults);
    }
  }
Runs performance tests.

The argument to this method should be an array of benchmark tests.  Each
element of the array is of the form {benchmark: function, label:name}

@param {!Array.<{benchmark:!function():*, label:string}>} benchmarks
    An array consisting of things we want to time, and the name to show
    for it in the performance table.
@param {number=} opt_numSamples Number of times to run the test functions.
    Defaults to 10.
@param {number=} opt_timeoutInterval Number of milliseconds after which the
    test is to be aborted. Defaults to 5000.
@return {!goog.Promise.<!Object.<!string,!Object>>} Performance stats
    promise. Promise will be resolved when last test completes.