Fix MemoryDumpManagerTest's thread unsafe usage of the base::TestIOThread API

base/test/test_io_thread.cc

Index: base/test/test_io_thread.cc
diff --git a/base/test/test_io_thread.cc b/base/test/test_io_thread.cc
index 1fa041251cbd9ed16b5b723f93954e07d4c8785a..ce4a8d10de27c74fdd9942c51c6c08811b2568ef 100644
--- a/base/test/test_io_thread.cc
+++ b/base/test/test_io_thread.cc
@@ -4,19 +4,7 @@
 
 #include "base/test/test_io_thread.h"
 
-#include "base/bind.h"
-#include "base/callback.h"
-#include "base/synchronization/waitable_event.h"
-
-namespace {
-
-void PostTaskAndWaitHelper(base::WaitableEvent* event,
-                           const base::Closure& task) {
-  task.Run();
-  event->Signal();
-}
-
-}  // namespace
+#include "base/logging.h"
 
 namespace base {
 
@@ -54,13 +42,4 @@ void TestIOThread::PostTask(const tracked_objects::Location& from_here,
   task_runner()->PostTask(from_here, task);
 }
 
-void TestIOThread::PostTaskAndWait(const tracked_objects::Location& from_here,
-                                   const base::Closure& task) {
-  base::WaitableEvent event(WaitableEvent::ResetPolicy::AUTOMATIC,
-                            WaitableEvent::InitialState::NOT_SIGNALED);
-  task_runner()->PostTask(from_here,
-                          base::Bind(&PostTaskAndWaitHelper, &event, task));
-  event.Wait();
-}
-
 }  // namespace base