Mojo: Convert the remaining OVERRIDEs to override in mojo/.

mojo/examples/wm_flow/app/app.cc

Index: mojo/examples/wm_flow/app/app.cc
diff --git a/mojo/examples/wm_flow/app/app.cc b/mojo/examples/wm_flow/app/app.cc
index b119877e84c3e50aaba00d810c6545b4fd868fd5..f2bea102be6abf855227d1ba59b43c4092515249 100644
--- a/mojo/examples/wm_flow/app/app.cc
+++ b/mojo/examples/wm_flow/app/app.cc
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #include "base/bind.h"
+#include "base/macros.h"
 #include "mojo/application/application_runner_chromium.h"
 #include "mojo/examples/wm_flow/app/embedder.mojom.h"
 #include "mojo/examples/wm_flow/embedded/embeddee.mojom.h"
@@ -33,7 +34,7 @@ class EmbedderImpl : public mojo::InterfaceImpl<Embedder> {
 
  private:
   // Overridden from Embedder:
-  virtual void HelloWorld(const mojo::Callback<void()>& callback) OVERRIDE {
+  virtual void HelloWorld(const mojo::Callback<void()>& callback) override {
     callback.Run();
   }