[Sync] Remove unneeded 'using syncer::' lines and 'syncer::' scopings

sync/syncable/nigori_util.h

Index: sync/syncable/nigori_util.h
diff --git a/sync/syncable/nigori_util.h b/sync/syncable/nigori_util.h
index 037c89e51259fc6d83fd1484069e78b73c02a3cc..2edc9cdff5df98cc2f76cdf40daec429d501a7bd 100644
--- a/sync/syncable/nigori_util.h
+++ b/sync/syncable/nigori_util.h
@@ -41,7 +41,7 @@ bool VerifyUnsyncedChangesAreEncrypted(
 // or unencrypted, based on |encrypted_types|.
 bool ProcessUnsyncedChangesForEncryption(
     WriteTransaction* const trans,
-    syncer::Cryptographer* cryptographer);
+    Cryptographer* cryptographer);
 
 // Returns true if the entry requires encryption but is not encrypted, false
 // otherwise. Note: this does not check that already encrypted entries are
@@ -56,7 +56,7 @@ bool SpecificsNeedsEncryption(ModelTypeSet encrypted_types,
 // Verifies all data of type |type| is encrypted appropriately.
 bool VerifyDataTypeEncryptionForTest(
     BaseTransaction* const trans,
-    syncer::Cryptographer* cryptographer,
+    Cryptographer* cryptographer,
     ModelType type,
     bool is_encrypted) WARN_UNUSED_RESULT;
 
@@ -64,7 +64,7 @@ bool VerifyDataTypeEncryptionForTest(
 // Returns false if an error encrypting occurred (does not modify |entry|).
 // Note: gracefully handles new_specifics aliasing with entry->Get(SPECIFICS).
 bool UpdateEntryWithEncryption(
-    syncer::Cryptographer* cryptographer,
+    Cryptographer* cryptographer,
     const sync_pb::EntitySpecifics& new_specifics,
     MutableEntry* entry);