Add a test for the workaround for bug 89967.

chrome/test/data/extensions/api_test/window_open/opener/test.html

+<script>
+chrome.test.runTests([
+  // Tests that even though window.opener is not set when using
+  // chrome.windows.create directly, the same effect can be achieved by creating
+  // a window, giving it a name, and then targetting that window via
+  // window.open().
+  function checkOpener() {
+    // Make sure that we wait for the load callbacks to fire.
+    var testCompleted = chrome.test.callbackAdded();
+    var testWindowId;
+    
+    window.onSetNameLoaded = function(testWindow) {
+      // It's not technically required for window.opener to be null when using
+      // chrome.windows.create, but that is the current expected behavior (and
+      // the reason why the window.name/open() workaround is necessary).
+      chrome.test.assertTrue(testWindow.opener == null);
+      window.open('check-opener.html', 'target-window');
+    };
+    
+    window.onCheckOpenerLoaded = function(testWindow) {
+      // The opener should now be set...
+      chrome.test.assertTrue(testWindow.opener != null);
+      // ...and the test window should only have one tab (because it was
+      // targetted via the "target-window" name).
+      chrome.tabs.getAllInWindow(
+          testWindowId,
+          chrome.test.callbackPass(function(tabs) {
+            chrome.test.assertEq(1, tabs.length);
+            chrome.test.assertEq(
+                chrome.extension.getURL('check-opener.html'), tabs[0].url);
+            testCompleted();      
+          }));
+    };
+    
+    chrome.windows.create(
+        {'url': 'set-name.html'},
+        chrome.test.callbackPass(function(win) {
+          testWindowId = win.id;
+        }));
+  }
+]);
+</script>