Make NSSCertDatabase::ListCerts work async on a worker thread.

chromeos/cert_loader.h

Index: chromeos/cert_loader.h
diff --git a/chromeos/cert_loader.h b/chromeos/cert_loader.h
index 5fd27ea339988207b5453f883b1ac30823d0d2d8..061160d0aacbe79d113fa8e47af6b55b6acce946 100644
--- a/chromeos/cert_loader.h
+++ b/chromeos/cert_loader.h
@@ -63,11 +63,6 @@ class CHROMEOS_EXPORT CertLoader : public net::CertDatabase::Observer {
   // The CertLoader will _not_ take the ownership of the database.
   void StartWithNSSDB(net::NSSCertDatabase* database);
 
-   // Sets the task runner that any slow calls will be made from, e.g. calls
-   // to the NSS database. If not set, uses base::WorkerPool.
-  void SetSlowTaskRunnerForTest(
-      const scoped_refptr<base::TaskRunner>& task_runner);
-
   void AddObserver(CertLoader::Observer* observer);
   void RemoveObserver(CertLoader::Observer* observer);
 
@@ -99,7 +94,7 @@ class CHROMEOS_EXPORT CertLoader : public net::CertDatabase::Observer {
   void LoadCertificates();
 
   // Called if a certificate load task is finished.
-  void UpdateCertificates(net::CertificateList* cert_list);
+  void UpdateCertificates(scoped_ptr<net::CertificateList> cert_list);
 
   void NotifyCertificatesLoaded(bool initial_load);
 
@@ -132,10 +127,6 @@ class CHROMEOS_EXPORT CertLoader : public net::CertDatabase::Observer {
 
   base::ThreadChecker thread_checker_;
 
-  // TaskRunner that, if set, replaces base::WorkerPool. Should only be set in
-  // tests.
-  scoped_refptr<base::TaskRunner> slow_task_runner_for_test_;
-
   base::WeakPtrFactory<CertLoader> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(CertLoader);