Worker: Introduce per-global-scope task scheduler

third_party/WebKit/public/platform/scheduler/child/worker_scheduler.h

Index: third_party/WebKit/public/platform/scheduler/child/worker_scheduler.h
diff --git a/third_party/WebKit/public/platform/scheduler/child/worker_scheduler.h b/third_party/WebKit/public/platform/scheduler/child/worker_scheduler.h
index 1d814b1c590db2c12dc460406808f69289af950a..8e3e4428f2df4902a0648405a3d577d32ec161f9 100644
--- a/third_party/WebKit/public/platform/scheduler/child/worker_scheduler.h
+++ b/third_party/WebKit/public/platform/scheduler/child/worker_scheduler.h
@@ -9,9 +9,10 @@
 
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
+#include "public/platform/WebCommon.h"
+#include "public/platform/scheduler/base/task_queue.h"
 #include "public/platform/scheduler/child/child_scheduler.h"
 #include "public/platform/scheduler/child/single_thread_idle_task_runner.h"
-#include "public/platform/WebCommon.h"
 
 namespace blink {
 namespace scheduler {
@@ -27,6 +28,9 @@ class BLINK_PLATFORM_EXPORT WorkerScheduler : public ChildScheduler {
   // initialization needed such as initializing idle period detection.
   virtual void Init() = 0;
 
+  virtual scoped_refptr<TaskQueue> NewUnthrottledTaskRunner(

[altimin, 2017/04/10 17:59:46]

I'll make your life more interesting: we're changing public/platform/child API
surface and are trying to narrow it down. TaskQueue will be definitely moved to
Source/platform/scheduler, I'll try to move WorkerScheduler too. I'll keep you
posted.

[Sami, 2017/04/11 09:53:06]

That shouldn't affect things here since this patch is all in Blink, right? We
may need to tweak the way threads are initialized from content but that should
be largely orthogonal.

[altimin, 2017/04/11 10:47:00]

Not exactly: this patch touches public/platform and will be affected by layering
improvements 

[nhiroki, 2017/04/12 08:54:45]

Thank you for the heads-up. I rebased / will rebase this on your CLs.

+      TaskQueue::QueueType queue_type) = 0;
+
  protected:
   WorkerScheduler();
   DISALLOW_COPY_AND_ASSIGN(WorkerScheduler);