[Extensions Bindings] Add a bindings/ subdirectory under renderer

extensions/renderer/bindings/api_bindings_system_unittest.h

 // Copyright 2017 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_API_BINDINGS_SYSTEM_UNITTEST_H_
-#define EXTENSIONS_RENDERER_API_BINDINGS_SYSTEM_UNITTEST_H_
+#ifndef EXTENSIONS_RENDERER_BINDINGS_API_BINDINGS_SYSTEM_UNITTEST_H_
+#define EXTENSIONS_RENDERER_BINDINGS_API_BINDINGS_SYSTEM_UNITTEST_H_
 
 #include <map>
 #include <memory>
 #include <string>
 
 #include "base/macros.h"
-#include "extensions/renderer/api_binding_test.h"
-#include "extensions/renderer/api_binding_types.h"
-#include "extensions/renderer/api_request_handler.h"
+#include "extensions/renderer/bindings/api_binding_test.h"
+#include "extensions/renderer/bindings/api_binding_types.h"
+#include "extensions/renderer/bindings/api_request_handler.h"
 #include "v8/include/v8.h"
 
 namespace base {
 class DictionaryValue;
 }
 
 namespace extensions {
 class APIBindingsSystem;
 
 // The base class to test the APIBindingsSystem. This allows subclasses to
@@ skipping 68 matching lines @@
 
   // The last request to be received from the APIBindingsSystem, or null if
   // there is none.
   std::unique_ptr<APIRequestHandler::Request> last_request_;
 
   DISALLOW_COPY_AND_ASSIGN(APIBindingsSystemTest);
 };
 
 }  // namespace extensions
 
-#endif  // EXTENSIONS_RENDERER_API_BINDINGS_SYSTEM_UNITTEST_H_
+#endif  // EXTENSIONS_RENDERER_BINDINGS_API_BINDINGS_SYSTEM_UNITTEST_H_