Add virtual to ~TitleWatcher to appease clang.

chrome/test/ui_test_utils.h

Index: chrome/test/ui_test_utils.h
diff --git a/chrome/test/ui_test_utils.h b/chrome/test/ui_test_utils.h
index cb3483155885b2e2323b55c391ce93a90e91c940..c7c126ca121ebd4027ad133b032e5e45470a9616 100644
--- a/chrome/test/ui_test_utils.h
+++ b/chrome/test/ui_test_utils.h
@@ -478,7 +478,7 @@ class TitleWatcher : public NotificationObserver {
   // entire lifetime of |this|. |expected_title| is the title that |this|
   // will wait for.
   TitleWatcher(TabContents* tab_contents, const string16& expected_title);
-  ~TitleWatcher();
+  virtual ~TitleWatcher();
 
   // Waits until the title for the tab is set to the |expected_title|
   // passed into the constructor.