[Extensions Bindings] Add a bindings/ subdirectory under renderer

extensions/renderer/bindings/api_event_handler.cc

 // Copyright 2016 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/api_event_handler.h"
+#include "extensions/renderer/bindings/api_event_handler.h"
 
 #include <algorithm>
 #include <map>
 #include <memory>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/supports_user_data.h"
 #include "base/values.h"
 #include "content/public/child/v8_value_converter.h"
-#include "extensions/renderer/api_event_listeners.h"
-#include "extensions/renderer/event_emitter.h"
+#include "extensions/renderer/bindings/api_event_listeners.h"
+#include "extensions/renderer/bindings/event_emitter.h"
 #include "gin/handle.h"
 #include "gin/per_context_data.h"
 
 namespace extensions {
 
 namespace {
 
 void DoNothingOnListenersChanged(binding::EventListenersChanged change,
                                  const base::DictionaryValue* filter,
                                  bool was_manual,
@@ skipping 296 matching lines @@
   auto iter = data->emitters.find(event_name);
   DCHECK(iter != data->emitters.end());
   EventEmitter* emitter = nullptr;
   gin::Converter<EventEmitter*>::FromV8(
       context->GetIsolate(), iter->second.Get(context->GetIsolate()), &emitter);
   CHECK(emitter);
   return emitter->GetNumListeners();
 }
 
 }  // namespace extensions