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

net/cert/nss_profile_filter_chromeos.cc

Index: net/cert/nss_profile_filter_chromeos.cc
diff --git a/net/cert/nss_profile_filter_chromeos.cc b/net/cert/nss_profile_filter_chromeos.cc
index 48718174e8b37a4f0626c95fce7340034e795bd5..847ee55a1e2de26c097339cb54322034d6a3a5fe 100644
--- a/net/cert/nss_profile_filter_chromeos.cc
+++ b/net/cert/nss_profile_filter_chromeos.cc
@@ -4,9 +4,8 @@
 
 #include "net/cert/nss_profile_filter_chromeos.h"
 
-#include "base/bind.h"
-#include "base/callback.h"
 #include "base/strings/stringprintf.h"
+#include "net/cert/x509_certificate.h"
 
 namespace net {
 
@@ -37,6 +36,17 @@ NSSProfileFilterChromeOS::NSSProfileFilterChromeOS() {}
 
 NSSProfileFilterChromeOS::~NSSProfileFilterChromeOS() {}
 
+scoped_ptr<NSSProfileFilterChromeOS>
+NSSProfileFilterChromeOS::CreateCopy() const {
+  scoped_ptr<NSSProfileFilterChromeOS> copy(new NSSProfileFilterChromeOS());
+  copy->Init(
+      crypto::ScopedPK11Slot(
+          public_slot_ ? PK11_ReferenceSlot(public_slot_.get()) : NULL),
+      crypto::ScopedPK11Slot(
+          private_slot_ ? PK11_ReferenceSlot(private_slot_.get()) : NULL));
+  return copy.Pass();
+}
+
 void NSSProfileFilterChromeOS::Init(crypto::ScopedPK11Slot public_slot,
                                     crypto::ScopedPK11Slot private_slot) {
   public_slot_ = public_slot.Pass();