[Extensions Bindings] Add a bindings/ subdirectory under renderer

extensions/renderer/storage_area.cc

 // 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.
 
 #include "extensions/renderer/storage_area.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/strings/stringprintf.h"
 #include "extensions/common/api/storage.h"
-#include "extensions/renderer/api_request_handler.h"
-#include "extensions/renderer/api_signature.h"
-#include "extensions/renderer/api_type_reference_map.h"
+#include "extensions/renderer/bindings/api_request_handler.h"
+#include "extensions/renderer/bindings/api_signature.h"
+#include "extensions/renderer/bindings/api_type_reference_map.h"
 #include "gin/arguments.h"
 #include "gin/handle.h"
 #include "gin/object_template_builder.h"
 #include "gin/wrappable.h"
 
 namespace extensions {
 
 namespace {
 
 #define DEFINE_STORAGE_AREA_HANDLERS()                            \
@@ skipping 172 matching lines @@
     return;
   }
 
   converted_arguments->Insert(0u, base::MakeUnique<base::Value>(name_));
   request_handler_->StartRequest(
       context, "storage." + method_name, std::move(converted_arguments),
       callback, v8::Local<v8::Function>(), binding::RequestThread::UI);
 }
 
 }  // namespace extensions