Modify some gc related layout tests to work with Ignition.

third_party/WebKit/LayoutTests/netinfo/gc-frame-listeners.html

Index: third_party/WebKit/LayoutTests/netinfo/gc-frame-listeners.html
diff --git a/third_party/WebKit/LayoutTests/netinfo/gc-frame-listeners.html b/third_party/WebKit/LayoutTests/netinfo/gc-frame-listeners.html
index 1112ed393c207bd74941034a63baff0fe5440d1c..12b385602dc06cfc4f6e1f907011ece09b715de8 100644
--- a/third_party/WebKit/LayoutTests/netinfo/gc-frame-listeners.html
+++ b/third_party/WebKit/LayoutTests/netinfo/gc-frame-listeners.html
@@ -11,42 +11,35 @@ description('Tests that listeners in closed frames are collected.');
 shouldBe('typeof window.internals.observeGC', '"function"',
 'this test requires window.internals');
 
-var childFrame = document.createElement('iframe');
-// Do not pass the object directly to observeGC function. This may
-// remain live on this function's stack preventing GC from collecting
-// it. Accessing the object inside an inner function will prevent any
-// unneeded references on this function's stack.
-var childFrameObserver = internals.observeGC((() => {return childFrame;})());
-
-document.body.appendChild(childFrame);
-
-var childConnection = childFrame.contentWindow.navigator.connection;
-// Do not pass the object directly to observeGC function. This may
-// remain live on this function's stack preventing GC from collecting
-// it. Accessing the object inside an inner function will prevent any
-// unneeded references on this function's stack.
-var childConnectionObserver = internals.observeGC((() => {return childConnection;})());
-
-var callback = function(e) {
-	testFailed("Should not get here.");
-};
-// Do not pass the object directly to observeGC function. This may
-// remain live on this function's stack preventing GC from collecting
-// it. Accessing the object inside an inner function will prevent any
-// unneeded references on this function's stack.
-var callbackObserver = internals.observeGC((() => {return callback;})());
-
-// Add the event listener and make sure it doesn't get collected.
-childConnection.addEventListener('typechange', callback);
-childConnection = null;
-callback = null;
+var childFrame;
+var childFrameObserver, childConnectionObserver, callbackObserver;
+
+// Do initialization work in an inner function to avoid references to
+// objects remaining live on this function's stack frame.
+// (http://crbug.com/595672/).
+(function() {
+    var callback = function(e) {
+	      testFailed("Should not get here.");
+    };
+
+    childFrame = document.createElement('iframe');
+    childFrameObserver = internals.observeGC(childFrame);
+    document.body.appendChild(childFrame);
+    var childConnection = childFrame.contentWindow.navigator.connection;
+    childConnectionObserver = internals.observeGC(childConnection);
+    callbackObserver = internals.observeGC(callback);
+    childConnection.addEventListener('typechange', callback);
+})();
+
 gc();
 childFrame.contentWindow.gc();
 shouldBeFalse('childFrameObserver.wasCollected');
 shouldBeFalse('childConnectionObserver.wasCollected');
 shouldBeFalse('callbackObserver.wasCollected');
 
-document.body.removeChild(childFrame);
+// Access objects in an inner function to avoid references to objects
+// remaining live on this function's stack frame (http://crbug.com/595672/).
+(() => {document.body.removeChild(childFrame);})();
 childFrame = null;
 gc();
 shouldBeTrue('childFrameObserver.wasCollected');