Add a test that is a repro case for bug 444945.

content/public/test/browser_test_utils.h

Index: content/public/test/browser_test_utils.h
diff --git a/content/public/test/browser_test_utils.h b/content/public/test/browser_test_utils.h
index 60b19c730c72be568e0aeb11a267ce9ec551833f..8bb877acd6e617e1cb209e64b83dce06e2c0bbee 100644
--- a/content/public/test/browser_test_utils.h
+++ b/content/public/test/browser_test_utils.h
@@ -351,6 +351,35 @@ class DOMMessageQueue : public NotificationObserver {
   DISALLOW_COPY_AND_ASSIGN(DOMMessageQueue);
 };
 
+// Used to wait for a new WebContents to be created. Instantiate this object
+// before the operation that will create the window.
+class WebContentsAddedObserver {
+ public:
+  WebContentsAddedObserver();
+  ~WebContentsAddedObserver();
+
+  // Will run a message loop to wait for the new window if it hasn't been
+  // created since the constructor
+  WebContents* GetWebContents();
+
+  // Will tell whether RenderViewCreated Callback has invoked
+  bool RenderViewCreatedCalled();
+
+ private:
+  class RenderViewCreatedObserver;
+
+  void WebContentsCreated(WebContents* web_contents);
+
+  // Callback to WebContentCreated(). Cached so that we can unregister it.
+  base::Callback<void(WebContents*)> web_contents_created_callback_;
+
+  WebContents* web_contents_;
+  scoped_ptr<RenderViewCreatedObserver> child_observer_;
+  scoped_refptr<MessageLoopRunner> runner_;
+
+  DISALLOW_COPY_AND_ASSIGN(WebContentsAddedObserver);
+};
+
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_TEST_BROWSER_TEST_UTILS_H_