Remove mojo::edk::test::ScopedIPCSupport

mojo/edk/system/core.cc

Index: mojo/edk/system/core.cc
diff --git a/mojo/edk/system/core.cc b/mojo/edk/system/core.cc
index cfcb777dfe7e03a8ebceb3e904848dd8209b4b8f..308c2879c4c3283007664f4a34dea5f582988e31 100644
--- a/mojo/edk/system/core.cc
+++ b/mojo/edk/system/core.cc
@@ -332,15 +332,7 @@ MojoResult Core::PassSharedMemoryHandle(
 }
 
 void Core::RequestShutdown(const base::Closure& callback) {
-  base::Closure on_shutdown;
-  if (base::ThreadTaskRunnerHandle::IsSet()) {
-    on_shutdown = base::Bind(base::IgnoreResult(&base::TaskRunner::PostTask),
-                             base::ThreadTaskRunnerHandle::Get(),
-                             FROM_HERE, callback);
-  } else {
-    on_shutdown = callback;
-  }
-  GetNodeController()->RequestShutdown(on_shutdown);
+  GetNodeController()->RequestShutdown(callback);
 }
 
 ScopedMessagePipeHandle Core::CreateMessagePipe(