Try running GC twice to fix flaky associatedFormControls-leak-nodes.html

third_party/WebKit/LayoutTests/fast/forms/associatedFormControls-leak-nodes.html

Index: third_party/WebKit/LayoutTests/fast/forms/associatedFormControls-leak-nodes.html
diff --git a/third_party/WebKit/LayoutTests/fast/forms/associatedFormControls-leak-nodes.html b/third_party/WebKit/LayoutTests/fast/forms/associatedFormControls-leak-nodes.html
index 40612b1c2fff41b453594618acc6694dc6d81454..f0743c3b91a9728b95449c09eca28e6ee4ae7ccf 100644
--- a/third_party/WebKit/LayoutTests/fast/forms/associatedFormControls-leak-nodes.html
+++ b/third_party/WebKit/LayoutTests/fast/forms/associatedFormControls-leak-nodes.html
@@ -12,20 +12,23 @@ if (!window.internals) {
     window.jsTestIsAsync = true;
     var documentsBefore;
     var documentsAfter;
+    // FIXME(keishi): Calling asyncGC twice to fix flakiness.
     asyncGC(function() {
-        documentsBefore = window.internals.numberOfLiveDocuments();
+        asyncGC(function() {
+            documentsBefore = window.internals.numberOfLiveDocuments();
 
-        var frame = document.getElementById('frame');
-        frame.contentDocument.body.innerHTML = '<form></form>';
-        document.body.removeChild(frame);
-        frame = null;
+            var frame = document.getElementById('frame');
+            frame.contentDocument.body.innerHTML = '<form></form>';
+            document.body.removeChild(frame);
+            frame = null;
 
-        asyncGC(function() {
-            documentsAfter = window.internals.numberOfLiveDocuments();
+            asyncGC(function() {
+                documentsAfter = window.internals.numberOfLiveDocuments();
 
-            // -1 is from removing frame itself.
-            shouldBe('documentsBefore - 1', 'documentsAfter');
-            finishJSTest();
+                // -1 is from removing frame itself.
+                shouldBe('documentsBefore - 1', 'documentsAfter');
+                finishJSTest();
+            });
         });
     });
 }