Introduce TaskRunnerHelper::get()

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 19a0983c82539672a0586d69189df381806c98a5..94e37e6d2f515799793e4913d3c9aaa14a090e6a 100644
--- a/third_party/WebKit/Source/core/dom/TaskRunnerHelper.h
+++ b/third_party/WebKit/Source/core/dom/TaskRunnerHelper.h
@@ -16,9 +16,45 @@ class LocalFrame;
 class ScriptState;
 class WebTaskRunner;
 
+enum TaskRunnerType {

[Sami, 2016/08/04 10:32:29]

FWIW we could use an enum class for this, e.g., TaskRunnerType::Networking. I'll
let you pick the style that best fits the rest of Blink :) The current scheme
requires less typing which is important too.

[haraken, 2016/08/04 13:45:31]

Used an enum class.

+    // Speced tasks and related internal tasks should be posted to one of
+    // the following task runners. These task runners may be throttled.
+    DOMManipulationTask,
+    UserInteractionTask,
+    NetworkingTask,
+    HistoryTraversalTask,
+    EmbedTask,
+    MediaElementEventTask,
+    CanvasBlobSerializationTask,
+    MicrotaskTask,
+    TimerTask,
+    RemoteEventTask,
+    WebSocketTask,
+    PostedMessageTask,
+    UnshippedPortMessageTask,
+
+    // Other internal tasks that cannot fit any of the above task runners
+    // can be posted here, but the usage is not encouraged. The task runner
+    // may be throttled.
+    InternalTask,
+
+    // Idle tasks should be posted here.
+    IdleTask,

[Sami, 2016/08/04 10:32:29]

Idle tasks need a different kind of task runner (one that gives them a
deadline), so it doesn't seem like we can support them with this API?

[haraken, 2016/08/04 13:45:31]

Agreed. Removed IdleTask.

+
+    // Tasks that must not be throttled should be posted here, but the usage
+    // should be very limited.
+    UnthrottledTask,
+};
+
 class CORE_EXPORT TaskRunnerHelper final {
     STATIC_ONLY(TaskRunnerHelper);
 public:
+    static WebTaskRunner* get(TaskRunnerType, LocalFrame*);
+    static WebTaskRunner* get(TaskRunnerType, Document*);
+    static WebTaskRunner* get(TaskRunnerType, ExecutionContext*);
+    static WebTaskRunner* get(TaskRunnerType, ScriptState*);
+
+    // TODO(haraken): Remove the following APIs.
     static WebTaskRunner* getUnthrottledTaskRunner(LocalFrame*);
     static WebTaskRunner* getTimerTaskRunner(LocalFrame*);
     static WebTaskRunner* getLoadingTaskRunner(LocalFrame*);