Enable system NSS key slot.

crypto/scoped_test_system_nss_key_slot.h

Index: crypto/scoped_test_system_nss_key_slot.h
diff --git a/crypto/scoped_test_system_nss_key_slot.h b/crypto/scoped_test_system_nss_key_slot.h
index 156504787f21dfe94c199fe110a73bc61758235d..2de1e7654e65a82da5db29f01e87037f058d33f4 100644
--- a/crypto/scoped_test_system_nss_key_slot.h
+++ b/crypto/scoped_test_system_nss_key_slot.h
@@ -9,24 +9,33 @@
 #include "base/memory/scoped_ptr.h"
 #include "crypto/crypto_export.h"
 
+// Forward declaration, from <pk11pub.h>
+typedef struct PK11SlotInfoStr PK11SlotInfo;
+
 namespace crypto {
 
 class ScopedTestNSSDB;
 
 // Opens a persistent NSS software database in a temporary directory and sets
 // the test system slot to the opened database. This helper should be created in
-// tests where no system token is provided by the Chaps module and before
-// InitializeTPMTokenAndSystemSlot is called. Then the opened test database will
+// tests where no system token is provided by the Chaps module.
+// If |skip_tpm_initialization| is true, then the TPM initialization that is
+// usually triggered by InitializeTPMTokenAndSystemSlot is skipped and instead
+// the |slot| is directly exposed through |GetSystemNSSKeySlot| and
+// |IsTPMTokenReady| will return true.
+// If |skip_tpm_initialization| is false, InitializeTPMTokenAndSystemSlot must
+// be called afterwards. Then the opened test database will
 // be used and the initialization continues as if Chaps had provided this test
-// database. In particular, the DB will be exposed by |GetSystemNSSKeySlot| and
+// database. Again, the DB will be exposed by |GetSystemNSSKeySlot| and
 // |IsTPMTokenReady| will return true.
 // At most one instance of this helper must be used at a time.
 class CRYPTO_EXPORT_PRIVATE ScopedTestSystemNSSKeySlot {
  public:
-  explicit ScopedTestSystemNSSKeySlot();
+  explicit ScopedTestSystemNSSKeySlot(bool skip_tpm_initialization);
   ~ScopedTestSystemNSSKeySlot();
 
   bool ConstructedSuccessfully() const;
+  PK11SlotInfo* slot() const;
 
  private:
   scoped_ptr<ScopedTestNSSDB> test_db_;