Revert of Worker: Introduce per-global-scope task scheduler

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

Index: third_party/WebKit/Source/core/dom/TaskRunnerHelper.h
diff --git a/third_party/WebKit/Source/core/dom/TaskRunnerHelper.h b/third_party/WebKit/Source/core/dom/TaskRunnerHelper.h
index 9389cdbcee5dd86f8dc2d2a10287962537eae4cd..d15176dc0dead87715ba29689b25106187b4e8cf 100644
--- a/third_party/WebKit/Source/core/dom/TaskRunnerHelper.h
+++ b/third_party/WebKit/Source/core/dom/TaskRunnerHelper.h
@@ -16,8 +16,6 @@
 class LocalFrame;
 class ScriptState;
 class WebTaskRunner;
-class WorkerOrWorkletGlobalScope;
-class WorkerThread;
 
 enum class TaskType : unsigned {
   // Speced tasks and related internal tasks should be posted to one of
@@ -148,14 +146,6 @@
   static RefPtr<WebTaskRunner> Get(TaskType, Document*);
   static RefPtr<WebTaskRunner> Get(TaskType, ExecutionContext*);
   static RefPtr<WebTaskRunner> Get(TaskType, ScriptState*);
-  static RefPtr<WebTaskRunner> Get(TaskType, WorkerOrWorkletGlobalScope*);
-
-  // Returns a WebTaskRunner that is associated to the worker / worklet global
-  // scope that corresponds to the given WorkerThread. Note that WorkerThread is
-  // a per-global-scope object while the naming might sound differently.
-  // TODO(nhiroki): Rename WorkerThread to something that clarifies it's a
-  // per-global-scope object.
-  static RefPtr<WebTaskRunner> Get(TaskType, WorkerThread*);
 };
 
 }  // namespace blink