Revert of Use TaskScheduler instead of WorkerPool in client_cert_store_chromeos.cc.

chrome/browser/chromeos/net/client_cert_store_chromeos_unittest.cc

Index: chrome/browser/chromeos/net/client_cert_store_chromeos_unittest.cc
diff --git a/chrome/browser/chromeos/net/client_cert_store_chromeos_unittest.cc b/chrome/browser/chromeos/net/client_cert_store_chromeos_unittest.cc
index 3621e9e11895081b8b4e6511432611506d4f8db2..c3c63f9bb7dc13f76d0cbe8b9c31ed8d091ef882 100644
--- a/chrome/browser/chromeos/net/client_cert_store_chromeos_unittest.cc
+++ b/chrome/browser/chromeos/net/client_cert_store_chromeos_unittest.cc
@@ -4,6 +4,7 @@
 
 #include "chrome/browser/chromeos/net/client_cert_store_chromeos.h"
 
+#include <memory>
 #include <string>
 
 #include "base/callback.h"
@@ -13,7 +14,6 @@
 #include "base/memory/ref_counted.h"
 #include "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
-#include "base/test/scoped_task_scheduler.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "chrome/browser/chromeos/certificate_provider/certificate_provider.h"
 #include "crypto/scoped_test_nss_db.h"
@@ -77,7 +77,7 @@ class TestCertFilter : public ClientCertStoreChromeOS::CertFilter {
 
 class ClientCertStoreChromeOSTest : public ::testing::Test {
  public:
-  ClientCertStoreChromeOSTest() {}
+  ClientCertStoreChromeOSTest() : message_loop_(new base::MessageLoopForIO()) {}
 
   scoped_refptr<net::X509Certificate> ImportCertToSlot(
       const std::string& cert_filename,
@@ -88,7 +88,7 @@ class ClientCertStoreChromeOSTest : public ::testing::Test {
   }
 
  private:
-  base::test::ScopedTaskScheduler scoped_task_scheduler_;
+  std::unique_ptr<base::MessageLoop> message_loop_;

[gab, 2017/02/28 01:42:40]

Can this just be a base::MessageLoopForIO member? Or even just a
base::MessageLoop (seems you didn't need an IO loop in reverted CL?)

 };
 
 // Ensure that cert requests, that are started before the filter is initialized,