Worker: Introduce per-global-scope task scheduler

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"
 #include "wtf/HashTraits.h"
 
 namespace blink {
 
 class Document;
 class ExecutionContext;
 class LocalFrame;
 class ScriptState;
 class WebTaskRunner;
+class WorkerThread;
 
 enum class TaskType : unsigned {
   // Speced tasks and related internal tasks should be posted to one of
   // the following task runners. These task runners may be throttled.
 
   // https://html.spec.whatwg.org/multipage/webappapis.html#generic-task-sources
   //
   // This task source is used for features that react to DOM manipulations, such
   // as things that happen in a non-blocking fashion when an element is inserted
   // into the document.
@@ skipping 110 matching lines @@
 // object. The posted tasks are guaranteed to run in a sequence if they have the
 // same TaskType and the context objects belong to the same frame.
 class CORE_EXPORT TaskRunnerHelper final {
   STATIC_ONLY(TaskRunnerHelper);
 
  public:
   static RefPtr<WebTaskRunner> get(TaskType, LocalFrame*);
   static RefPtr<WebTaskRunner> get(TaskType, Document*);
   static RefPtr<WebTaskRunner> get(TaskType, ExecutionContext*);
   static RefPtr<WebTaskRunner> get(TaskType, ScriptState*);
+  static RefPtr<WebTaskRunner> get(TaskType, WorkerThread*);
 };
 
 }  // namespace blink
 
 #endif