Always use an async TaskScheduler in TestBrowserThreadBundle.

content/public/test/test_browser_thread_bundle.cc

Index: content/public/test/test_browser_thread_bundle.cc
diff --git a/content/public/test/test_browser_thread_bundle.cc b/content/public/test/test_browser_thread_bundle.cc
index cc35627cded0adf9701e1b24b70b5f1bf2eca03f..c0c4b4f5f965834fd74aa3380f01b8318787c612 100644
--- a/content/public/test/test_browser_thread_bundle.cc
+++ b/content/public/test/test_browser_thread_bundle.cc
@@ -9,7 +9,6 @@
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/test/scoped_async_task_scheduler.h"
-#include "base/test/scoped_task_scheduler.h"
 #include "content/browser/browser_thread_impl.h"
 #include "content/public/test/test_browser_thread.h"
 
@@ -58,7 +57,6 @@ TestBrowserThreadBundle::~TestBrowserThreadBundle() {
   base::RunLoop().RunUntilIdle();
 
   scoped_async_task_scheduler_.reset();
-  scoped_task_scheduler_.reset();
 
   // |message_loop_| needs to explicitly go away before fake threads in order
   // for DestructionObservers hooked to |message_loop_| to be able to invoke
@@ -92,13 +90,8 @@ void TestBrowserThreadBundle::Init() {
 void TestBrowserThreadBundle::CreateThreads() {
   DCHECK(!threads_created_);
 
-  if (options_ & REAL_TASK_SCHEDULER) {
-    scoped_async_task_scheduler_ =
-        base::MakeUnique<base::test::ScopedAsyncTaskScheduler>();
-  } else {
-    scoped_task_scheduler_ =
-        base::MakeUnique<base::test::ScopedTaskScheduler>(message_loop_.get());
-  }
+  scoped_async_task_scheduler_ =
+      base::MakeUnique<base::test::ScopedAsyncTaskScheduler>();
 
   if (options_ & REAL_DB_THREAD) {
     db_thread_.reset(new TestBrowserThread(BrowserThread::DB));