Fix some clang errors on Android.

base/test/test_support_android.cc

Index: base/test/test_support_android.cc
diff --git a/base/test/test_support_android.cc b/base/test/test_support_android.cc
index 82271d625d713c12fea2e880878e5c7ab80a9627..6ba69fe0a5a2453ded0b1df121510b9fdf74a15b 100644
--- a/base/test/test_support_android.cc
+++ b/base/test/test_support_android.cc
@@ -132,6 +132,9 @@ class MessagePumpForUIStub : public base::MessagePumpForUI {
       const base::TimeTicks& delayed_work_time) OVERRIDE {
     Waitable::GetInstance()->Signal();
   }
+
+ protected:
+  virtual ~MessagePumpForUIStub() {}
 };
 
 base::MessagePump* CreateMessagePumpForUIStub() {