Mojo: Convert OVERRIDE -> override in mojo/{embedder,system}.

mojo/system/remote_message_pipe_unittest.cc

Index: mojo/system/remote_message_pipe_unittest.cc
diff --git a/mojo/system/remote_message_pipe_unittest.cc b/mojo/system/remote_message_pipe_unittest.cc
index de4f859a51ea8c581d5ebef60f5c33ac74951853..21acd24a87f1af39c698fb6c0ee04106c32b02e7 100644
--- a/mojo/system/remote_message_pipe_unittest.cc
+++ b/mojo/system/remote_message_pipe_unittest.cc
@@ -45,14 +45,14 @@ class RemoteMessagePipeTest : public testing::Test {
   RemoteMessagePipeTest() : io_thread_(base::TestIOThread::kAutoStart) {}
   virtual ~RemoteMessagePipeTest() {}
 
-  virtual void SetUp() OVERRIDE {
+  virtual void SetUp() override {
     io_thread_.PostTaskAndWait(
         FROM_HERE,
         base::Bind(&RemoteMessagePipeTest::SetUpOnIOThread,
                    base::Unretained(this)));
   }
 
-  virtual void TearDown() OVERRIDE {
+  virtual void TearDown() override {
     io_thread_.PostTaskAndWait(
         FROM_HERE,
         base::Bind(&RemoteMessagePipeTest::TearDownOnIOThread,