Worker: Introduce per-global-scope task scheduler

third_party/WebKit/Source/core/workers/WorkerEventQueue.cpp

Index: third_party/WebKit/Source/core/workers/WorkerEventQueue.cpp
diff --git a/third_party/WebKit/Source/core/workers/WorkerEventQueue.cpp b/third_party/WebKit/Source/core/workers/WorkerEventQueue.cpp
index de9b2d7290cfac72a4c81af035c11e963bc65a22..ee47da55f63f61dfd739361b24a07b0bf25a55f8 100644
--- a/third_party/WebKit/Source/core/workers/WorkerEventQueue.cpp
+++ b/third_party/WebKit/Source/core/workers/WorkerEventQueue.cpp
@@ -26,6 +26,7 @@
 
 #include "core/workers/WorkerEventQueue.h"
 
+#include "core/dom/TaskRunnerHelper.h"
 #include "core/events/Event.h"
 #include "core/probe/CoreProbes.h"
 #include "core/workers/WorkerGlobalScope.h"
@@ -57,10 +58,11 @@ bool WorkerEventQueue::enqueueEvent(Event* event) {
   probe::asyncTaskScheduled(event->target()->getExecutionContext(),
                             event->type(), event);
   m_pendingEvents.insert(event);
-  m_workerGlobalScope->thread()->postTask(
-      BLINK_FROM_HERE,
-      WTF::bind(&WorkerEventQueue::dispatchEvent, wrapPersistent(this),
-                wrapWeakPersistent(event)));
+  // TODO(nhiroki): Callers of enqueueEvent() should specify the task type.
+  TaskRunnerHelper::get(TaskType::MiscPlatformAPI, m_workerGlobalScope.get())
+      ->postTask(BLINK_FROM_HERE,
+                 WTF::bind(&WorkerEventQueue::dispatchEvent,
+                           wrapPersistent(this), wrapWeakPersistent(event)));
   return true;
 }