[Sync] Move //sync to //components/sync.

sync/js/js_event_handler.h

-// Copyright 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 SYNC_JS_JS_EVENT_HANDLER_H_
-#define SYNC_JS_JS_EVENT_HANDLER_H_
-
-// See README.js for design comments.
-
-#include <string>
-
-#include "sync/base/sync_export.h"
-
-namespace syncer {
-
-class JsEventDetails;
-
-// An interface for objects that handle Javascript events (e.g.,
-// WebUIs).
-class SYNC_EXPORT JsEventHandler {
- public:
-  virtual void HandleJsEvent(
-      const std::string& name, const JsEventDetails& details) = 0;
-
- protected:
-  virtual ~JsEventHandler() {}
-};
-
-}  // namespace syncer
-
-#endif  // SYNC_JS_JS_EVENT_HANDLER_H_