Remove deprecated ExecutionContextTask

third_party/WebKit/Source/core/testing/NullExecutionContext.h

Index: third_party/WebKit/Source/core/testing/NullExecutionContext.h
diff --git a/third_party/WebKit/Source/core/testing/NullExecutionContext.h b/third_party/WebKit/Source/core/testing/NullExecutionContext.h
index fe41a7bc98567fe78f1b1b2ed3d12ea241e6ba39..e37205e56eb53661c1e82437fe87503644c7676c 100644
--- a/third_party/WebKit/Source/core/testing/NullExecutionContext.h
+++ b/third_party/WebKit/Source/core/testing/NullExecutionContext.h
@@ -30,12 +30,6 @@ class NullExecutionContext
   void DisableEval(const String&) override {}
   String UserAgent() const override { return String(); }
 
-  void PostTask(
-      TaskType,
-      const WebTraceLocation&,
-      std::unique_ptr<ExecutionContextTask>,
-      const String& task_name_for_instrumentation = g_empty_string) override;
-
   EventTarget* ErrorEventTarget() override { return nullptr; }
   EventQueue* GetEventQueue() const override { return queue_.Get(); }