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 d15176dc0dead87715ba29689b25106187b4e8cf..c935980eb9e862cc1ab7aa99af1dcd403a37c1ef 100644
--- a/third_party/WebKit/Source/core/dom/TaskRunnerHelper.h
+++ b/third_party/WebKit/Source/core/dom/TaskRunnerHelper.h
@@ -16,6 +16,8 @@ class ExecutionContext;
 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
@@ -146,6 +148,13 @@ class CORE_EXPORT TaskRunnerHelper final {
   static RefPtr<WebTaskRunner> Get(TaskType, Document*);
   static RefPtr<WebTaskRunner> Get(TaskType, ExecutionContext*);
   static RefPtr<WebTaskRunner> Get(TaskType, ScriptState*);
+  static RefPtr<WebTaskRunner> Get(TaskType, WorkerOrWorkletGlobalScope*);
+
+  // Passing WorkerThread could be confusing but it's valid because WorkerThread

[kinuko, 2017/04/17 05:01:11]

Maybe it'd be clearer to document what this Get does before noting this caveat
(E.g. "Returns WebTaskRunners that are associated to the worker 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, 2017/04/17 11:03:46]

Yeah, that makes it much clearer. Done.

+  // has one-to-one relationship with a context object.
+  // TODO(nhiroki): Rename WorkerThread to something that clarifies it's a
+  // per-global-scope object.
+  static RefPtr<WebTaskRunner> Get(TaskType, WorkerThread*);
 };
 
 }  // namespace blink