Move extensions bindings code out of //chrome

extensions/renderer/context_menus_custom_bindings.h

+// Copyright (c) 2012 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 EXTENSIONS_RENDERER_CONTEXT_MENUS_CUSTOM_BINDINGS_H_
+#define EXTENSIONS_RENDERER_CONTEXT_MENUS_CUSTOM_BINDINGS_H_
+
+#include "extensions/renderer/object_backed_native_handler.h"
+
+namespace extensions {
+class ScriptContext;
+
+// Implements custom bindings for the contextMenus API.
+class ContextMenusCustomBindings : public ObjectBackedNativeHandler {
+ public:
+  ContextMenusCustomBindings(ScriptContext* context);
+};
+
+}  // extensions
+
+#endif  // EXTENSIONS_RENDERER_CONTEXT_MENUS_CUSTOM_BINDINGS_H_