shouldBecomeEqual() behaves as shouldBe() if the testing expression returns the expected value

LayoutTests/resources/js-test.js

 // js-test now supports lazily printing test results which dumps all test
 // results once at the end of the test instead of building them up. To enable
 // this option, call setPrintTestResultsLazily() before running any tests.
 var _lazyTestResults; // Set by setPrintTestResultsLazily().
 
 // svg/dynamic-updates tests set enablePixelTesting=true, as we want to dump text + pixel results
 if (self.testRunner) {
     if (self.enablePixelTesting)
         testRunner.dumpAsTextWithPixelResults();
     else
@@ skipping 273 matching lines @@
 
 function shouldBecomeEqual(_a, _b, _completionHandler, _timeout)
 {
   if (typeof _a != "string" || typeof _b != "string")
     debug("WARN: shouldBecomeEqual() expects string arguments");
 
   if (_timeout === undefined)
     _timeout = 500;
 
   var _bv;
-  var _condition = function() {
+  function _condition() {
     var _exception;
     var _av;
     try {
       _av = eval(_a);
     } catch (e) {
         _exception = e;
     }
     _bv = eval(_b);
     if (_exception)
       testFailed(_a + " should become " + _bv + ". Threw exception " + _exception);
     if (isResultCorrect(_av, _bv)) {
       testPassed(_a + " became " + _b);
       return true;
     }
     return false;
   };
   var _failureTime = Date.now() + _timeout;
   var _failureHandler = function () {
     testFailed(_a + " failed to change to " + _bv + " in " + (_timeout / 1000) + " seconds.");
     _completionHandler();
   };
-  _waitForCondition(_condition, _failureTime, _completionHandler, _failureHandler);
+  setTimeout(_waitForCondition, 5, _condition, _failureTime, _completionHandler, _failureHandler);

[please use gerrit instead, 2015/02/17 16:28:48]

I'm still quite queasy about this change. We are slowing down each one of our
tests by 5 seconds? That's bad.

[yosin_UTC9, 2016/09/01 01:49:07]

It is "5ms" instead of "5s".
https://developer.mozilla.org/en-US/docs/Web/API/WindowTimers/setTimeout

Could you have |const| variable to describe unit of delay?
e.g. const kDelayMilliseconds = 5;

BTW, 5ms is too small, since frame rate is 60Hz. 16ms may be enough.

 }
 
 function shouldBecomeEqualToString(value, reference, completionHandler, timeout)
 {
   if (typeof value !== "string" || typeof reference !== "string")
     debug("WARN: shouldBecomeEqualToString() expects string arguments");
   var unevaledString = JSON.stringify(reference);
   shouldBecomeEqual(value, unevaledString, completionHandler, timeout);
 }
 
@@ skipping 77 matching lines @@
 }
 
 function shouldBecomeDifferent(_a, _b, _completionHandler, _timeout)
 {
   if (typeof _a != "string" || typeof _b != "string")
     debug("WARN: shouldBecomeDifferent() expects string arguments");
   if (_timeout === undefined)
     _timeout = 500;
 
   var _bv;
-  var _condition = function() {
+  function _condition() {
     var _exception;
     var _av;
     try {
       _av = eval(_a);
     } catch (e) {
       _exception = e;
     }
     _bv = eval(_b);
     if (_exception)
       testFailed(_a + " should became not equal to " + _bv + ". Threw exception " + _exception);
     if (!isResultCorrect(_av, _bv)) {
       testPassed(_a + " became different from " + _b);
       return true;
     }
     return false;
   };
   var _failureTime = Date.now() + _timeout;
   var _failureHandler = function () {
     testFailed(_a + " did not become different from " + _bv + " in " + (_timeout / 1000) + " seconds.");
     _completionHandler();
   };
-  _waitForCondition(_condition, _failureTime, _completionHandler, _failureHandler);
+  setTimeout(_waitForCondition, 5, _condition, _failureTime, _completionHandler, _failureHandler);
 }
 
 function shouldBeTrue(a, quiet) { shouldBe(a, "true", quiet); }
 function shouldBeTrueQuiet(a) { shouldBe(a, "true", true); }
 function shouldBeFalse(a, quiet) { shouldBe(a, "false", quiet); }
 function shouldBeNaN(a, quiet) { shouldBe(a, "NaN", quiet); }
 function shouldBeNull(a, quiet) { shouldBe(a, "null", quiet); }
 function shouldBeZero(a, quiet) { shouldBe(a, "0", quiet); }
 
 function shouldBeEqualToString(a, b)
@@ skipping 424 matching lines @@
     testPassed = function(msg) {
         workerPort.postMessage('PASS:' + msg);
     };
     finishJSTest = function() {
         workerPort.postMessage('DONE:');
     };
     debug = function(msg) {
         workerPort.postMessage(msg);
     };
 }