Replace the test for r158993 with a less flaky one

LayoutTests/fullscreen/full-screen-popup.html

Index: LayoutTests/fullscreen/full-screen-popup.html
diff --git a/LayoutTests/fullscreen/full-screen-enter-leave-enter.html b/LayoutTests/fullscreen/full-screen-popup.html
similarity index 56%
rename from LayoutTests/fullscreen/full-screen-enter-leave-enter.html
rename to LayoutTests/fullscreen/full-screen-popup.html
index b39dee802ef393f8e6c847ea2664f56b3f7c55a1..1171dd953cb9171650749b1161be6af131f52d03 100644
--- a/LayoutTests/fullscreen/full-screen-enter-leave-enter.html
+++ b/LayoutTests/fullscreen/full-screen-popup.html
@@ -7,19 +7,20 @@
         logResult(false, "Element.prototype.webkitRequestFullScreen == undefined");
         endTest();
     } else {
+        if (window.testRunner) {
+            testRunner.setCanOpenWindows();
+            testRunner.setPopupBlockingEnabled(true);
+            testRunner.setCloseRemainingWindowsWhenComplete(true);
+        }
         var span = document.getElementsByTagName('span')[0];
 
-        var enterLeaveEnter = function() {
-            testExpected("document.webkitIsFullScreen", false);
-            testExpected("document.webkitCurrentFullScreenElement", undefined);
+        var fullScreenAndPopup = function() {
             span.webkitRequestFullScreen();
+            testExpected("window.open('about:blank')", null);
             document.webkitCancelFullScreen();
-            span.webkitRequestFullScreen();
-            testExpected("document.webkitIsFullScreen", false);
-            testExpected("document.webkitCurrentFullScreenElement", undefined);
             setTimeout(endTest, 0);
         };
 
-        runWithKeyDown(enterLeaveEnter);
+        runWithKeyDown(fullScreenAndPopup);
     }
 </script>