Thread-safe version of PassphraseType.

components/sync/core/sync_encryption_handler.h

Index: components/sync/core/sync_encryption_handler.h
diff --git a/components/sync/core/sync_encryption_handler.h b/components/sync/core/sync_encryption_handler.h
index 09a6298e734764db28de5812a0db41eded95e402..41a7b95e5a5738d6756fdc02603c247545f694d3 100644
--- a/components/sync/core/sync_encryption_handler.h
+++ b/components/sync/core/sync_encryption_handler.h
@@ -166,10 +166,6 @@ class SyncEncryptionHandler {
   // types are encrypted.
   virtual bool IsEncryptEverythingEnabled() const = 0;
 
-  // Returns the current state of the passphrase needed to decrypt the
-  // bag of encryption keys in the nigori node.
-  virtual PassphraseType GetPassphraseType() const = 0;
-
   // The set of types that are always encrypted.
   static ModelTypeSet SensitiveTypes();
 };