Move AcceptWithResponder() out of the MessageReceiver interface.

mojo/public/cpp/bindings/tests/router_unittest.cc

Index: mojo/public/cpp/bindings/tests/router_unittest.cc
diff --git a/mojo/public/cpp/bindings/tests/router_unittest.cc b/mojo/public/cpp/bindings/tests/router_unittest.cc
index 980553c402c1e46d2197a22820613f18f243c00e..9ae61cd39bc01059aa3414dabfa8d0b43841e6c7 100644
--- a/mojo/public/cpp/bindings/tests/router_unittest.cc
+++ b/mojo/public/cpp/bindings/tests/router_unittest.cc
@@ -42,16 +42,11 @@ class MessageAccumulator : public MessageReceiver {
     return true;
   }
 
-  virtual bool AcceptWithResponder(Message* message, MessageReceiver* responder)
-      MOJO_OVERRIDE {
-    return false;
-  }
-
  private:
   internal::MessageQueue* queue_;
 };
 
-class ResponseGenerator : public MessageReceiver {
+class ResponseGenerator : public MessageReceiverWithResponder {
  public:
   ResponseGenerator() {
   }