Export TaskRunnerHelper functions to expose it to modules/

third_party/WebKit/Source/core/dom/TaskRunnerHelper.h

 // 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.
 
 #ifndef TaskRunnerHelper_h
 #define TaskRunnerHelper_h
 
+#include "core/CoreExport.h"
 #include "wtf/Allocator.h"
 
 namespace blink {
 
 class Document;
 class ExecutionContext;
 class LocalFrame;
 class ScriptState;
 class WebTaskRunner;
 
-class TaskRunnerHelper final {
+class CORE_EXPORT TaskRunnerHelper final {
     STATIC_ONLY(TaskRunnerHelper);
 public:
     static WebTaskRunner* getUnthrottledTaskRunner(LocalFrame*);
     static WebTaskRunner* getTimerTaskRunner(LocalFrame*);
     static WebTaskRunner* getLoadingTaskRunner(LocalFrame*);
     static WebTaskRunner* getUnthrottledTaskRunner(Document*);
     static WebTaskRunner* getTimerTaskRunner(Document*);
     static WebTaskRunner* getLoadingTaskRunner(Document*);
     static WebTaskRunner* getUnthrottledTaskRunner(ExecutionContext*);
     static WebTaskRunner* getUnthrottledTaskRunner(ScriptState*);
 };
 
 } // namespace blink
 
 #endif