Mojo: Unify the disparate source and header files into 3

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

Index: mojo/public/bindings/generators/cpp_templates/interface.h-template
diff --git a/mojo/public/bindings/generators/cpp_templates/interface.h-template b/mojo/public/bindings/generators/cpp_templates/interface.h-template
deleted file mode 100644
index 42946aa33eff0ab43d0e4a39d7d307b7e5775d72..0000000000000000000000000000000000000000
--- a/mojo/public/bindings/generators/cpp_templates/interface.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/bindings.h"
-
-namespace $NAMESPACE {
-$FORWARDS
-
-class $CLASS {
- public:
-$METHODS
-};
-
-}  // namespace $NAMESPACE
-
-#endif  // $HEADER_GUARD