Mojo: Unify the disparate source and header files into 3

mojo/public/bindings/generators/cpp_templates/interface_stub.h-template

Index: mojo/public/bindings/generators/cpp_templates/interface_stub.h-template
diff --git a/mojo/public/bindings/generators/cpp_templates/interface_stub.h-template b/mojo/public/bindings/generators/cpp_templates/interface_stub.h-template
deleted file mode 100644
index 0a35e9edbcca6c32e7a0f2ec881e3fe9a33ea297..0000000000000000000000000000000000000000
--- a/mojo/public/bindings/generators/cpp_templates/interface_stub.h-template
+++ /dev/null
@@ -1,20 +0,0 @@
-// Copyright $YEAR The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef $HEADER_GUARD
-#define $HEADER_GUARD
-
-#include "mojo/public/bindings/lib/message.h"
-#include "$HEADER"
-
-namespace $NAMESPACE {
-
-class ${CLASS}Stub : public $CLASS, public mojo::MessageReceiver {
- public:
-  virtual bool Accept(mojo::Message* message) MOJO_OVERRIDE;
-};
-
-}  // namespace $NAMESPACE
-
-#endif  // $HEADER_GUARD