mojo: break struct headers into headers and source

mojo/public/bindings/generators/cpp_interface.template

Index: mojo/public/bindings/generators/cpp_interface.template
diff --git a/mojo/public/bindings/generators/cpp_interface.template b/mojo/public/bindings/generators/cpp_interface.template
deleted file mode 100644
index 874e2f4870771d9bf776527274e561b9532ea9b9..0000000000000000000000000000000000000000
--- a/mojo/public/bindings/generators/cpp_interface.template
+++ /dev/null
@@ -1,19 +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 {
-
-class $classname {
- public:
-$methods
-};
-
-}  // namespace $namespace
-
-#endif  // $header_guard