DevTools: simplify the async instrumentation harness.

third_party/WebKit/Source/core/inspector/InspectorInstrumentation.h

Index: third_party/WebKit/Source/core/inspector/InspectorInstrumentation.h
diff --git a/third_party/WebKit/Source/core/inspector/InspectorInstrumentation.h b/third_party/WebKit/Source/core/inspector/InspectorInstrumentation.h
index a18191346227657f87a31d9424cd982d18b37496..992ce2386acfb5fa93be676ce1d3ad891cf067a8 100644
--- a/third_party/WebKit/Source/core/inspector/InspectorInstrumentation.h
+++ b/third_party/WebKit/Source/core/inspector/InspectorInstrumentation.h
@@ -82,6 +82,17 @@ private:
 
 namespace InspectorInstrumentation {
 
+class CORE_EXPORT AsyncTask {
+    STACK_ALLOCATED();
+public:
+    AsyncTask(ExecutionContext*, void* task);
+    ~AsyncTask();
+
+private:
+    Member<ExecutionContext> m_context;
+    void* m_task;
+};
+
 class CORE_EXPORT FrontendCounter {
     STATIC_ONLY(FrontendCounter);
 private: