[Blink>MediaSession] Use setActionCallback() instead of event listeners for media control actions

third_party/WebKit/Source/bindings/modules/v8/custom/V8MediaSessionCustom.cpp

+// 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 "bindings/modules/v8/V8MediaSession.h"
+
+#include "bindings/core/v8/V8DOMWrapper.h"
+#include "modules/mediasession/MediaSession.h"
+
+namespace blink {
+
+void V8MediaSession::visitDOMWrapperCustom(
+    v8::Isolate* isolate,
+    ScriptWrappable* scriptWrappable,
+    const v8::Persistent<v8::Object>& wrapper) {
+  scriptWrappable->toImpl<MediaSession>()->setV8ReferencesForHandlers(isolate,
+                                                                      wrapper);
+}
+
+}  // namespace blink