Fix XMLHttpRequest leak document when send() is called multiple times.

LayoutTests/fast/js/resources/leak-check.js

Index: LayoutTests/fast/js/resources/leak-check.js
diff --git a/LayoutTests/fast/dom/resources/leak-check.js b/LayoutTests/fast/js/resources/leak-check.js
similarity index 82%
rename from LayoutTests/fast/dom/resources/leak-check.js
rename to LayoutTests/fast/js/resources/leak-check.js
index 0a74f2b7f5e8c101f2e22329099befd1607abae7..efc56d83bf687037a4624bdc81c92b569cbf6204 100644
--- a/LayoutTests/fast/dom/resources/leak-check.js
+++ b/LayoutTests/fast/js/resources/leak-check.js
@@ -50,9 +50,14 @@ function doLeakTest(src, tolerance) {
             loadSourceIntoIframe('about:blank', function() {
                 // target document unloaded...
 
-                var countersAfter = getCounterValues();
-                compareValues(countersBefore, countersAfter, tolerance);
-                finishJSTest();
+                // Measure counter values on next timer event. This is needed
+                // to correctly handle deref cycles for some ActiveDOMObjects
+                // such as XMLHttpRequest.
+                setTimeout(function() {
+                    var countersAfter = getCounterValues();
+                    compareValues(countersBefore, countersAfter, tolerance);
+                    finishJSTest();
+                }, 100);
             });
         });
     });