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

net/ssl/client_cert_store_chromeos.cc

Index: net/ssl/client_cert_store_chromeos.cc
diff --git a/net/ssl/client_cert_store_chromeos.cc b/net/ssl/client_cert_store_chromeos.cc
index f357797e34b5d18b87766d81eaf1a42452635950..4caa6b23a2193136dd2010bb5b4fe48000868c65 100644
--- a/net/ssl/client_cert_store_chromeos.cc
+++ b/net/ssl/client_cert_store_chromeos.cc
@@ -16,7 +16,8 @@ ClientCertStoreChromeOS::ClientCertStoreChromeOS(
     const std::string& username_hash,
     const PasswordDelegateFactory& password_delegate_factory)
     : ClientCertStoreNSS(password_delegate_factory),
-      username_hash_(username_hash) {}
+      username_hash_(username_hash),
+      profile_filter_(new NSSProfileFilterChromeOS()) {}
 
 ClientCertStoreChromeOS::~ClientCertStoreChromeOS() {}
 
@@ -62,7 +63,7 @@ void ClientCertStoreChromeOS::DidGetPrivateSlot(
     CertificateList* selected_certs,
     const base::Closure& callback,
     crypto::ScopedPK11Slot private_slot) {
-  profile_filter_.Init(crypto::GetPublicSlotForChromeOSUser(username_hash_),
+  profile_filter_->Init(crypto::GetPublicSlotForChromeOSUser(username_hash_),
                        private_slot.Pass());
   ClientCertStoreNSS::GetClientCerts(*request, selected_certs, callback);
 }
@@ -70,7 +71,7 @@ void ClientCertStoreChromeOS::DidGetPrivateSlot(
 void ClientCertStoreChromeOS::InitForTesting(
     crypto::ScopedPK11Slot public_slot,
     crypto::ScopedPK11Slot private_slot) {
-  profile_filter_.Init(public_slot.Pass(), private_slot.Pass());
+  profile_filter_->Init(public_slot.Pass(), private_slot.Pass());
 }
 
 bool ClientCertStoreChromeOS::SelectClientCertsForTesting(