Update {virtual,override} to follow C++11 style in jingle.

jingle/notifier/listener/xmpp_push_client_unittest.cc

Index: jingle/notifier/listener/xmpp_push_client_unittest.cc
diff --git a/jingle/notifier/listener/xmpp_push_client_unittest.cc b/jingle/notifier/listener/xmpp_push_client_unittest.cc
index bd0b46de13c2119c8fa98e2ad5d0f56aa93bd4e2..abe6775b9a66c564e03c55f11c082f0c53becfb1 100644
--- a/jingle/notifier/listener/xmpp_push_client_unittest.cc
+++ b/jingle/notifier/listener/xmpp_push_client_unittest.cc
@@ -38,14 +38,14 @@ class XmppPushClientTest : public testing::Test {
             message_loop_.message_loop_proxy());
   }
 
-  virtual ~XmppPushClientTest() {}
+  ~XmppPushClientTest() override {}
 
-  virtual void SetUp() override {
+  void SetUp() override {
     xmpp_push_client_.reset(new XmppPushClient(notifier_options_));
     xmpp_push_client_->AddObserver(&mock_observer_);
   }
 
-  virtual void TearDown() override {
+  void TearDown() override {
     // Clear out any messages posted by XmppPushClient.
     message_loop_.RunUntilIdle();
     xmpp_push_client_->RemoveObserver(&mock_observer_);