Revert of sync: Add non-blocking type encryption support

sync/engine/model_type_entity.h

Index: sync/engine/model_type_entity.h
diff --git a/sync/engine/model_type_entity.h b/sync/engine/model_type_entity.h
index e05d469582ca0e4d383671f7cce0dc2839e049a1..abc67a95a4d3026dfc455e04bb5df8cdb4b0f75c 100644
--- a/sync/engine/model_type_entity.h
+++ b/sync/engine/model_type_entity.h
@@ -46,8 +46,7 @@
       const sync_pb::EntitySpecifics& specifics,
       bool deleted,
       base::Time ctime,
-      base::Time mtime,
-      const std::string& encryption_key_name);
+      base::Time mtime);
 
   // TODO(rlarocque): Implement FromDisk constructor when we implement storage.
 
@@ -80,16 +79,10 @@
   void ApplyUpdateFromServer(int64 update_version,
                              bool deleted,
                              const sync_pb::EntitySpecifics& specifics,
-                             base::Time mtime,
-                             const std::string& encryption_key_name);
+                             base::Time mtime);
 
   // Applies a local change to this item.
   void MakeLocalChange(const sync_pb::EntitySpecifics& specifics);
-
-  // Schedule a commit if the |name| does not match this item's last known
-  // encryption key.  The worker that performs the commit is expected to
-  // encrypt the item using the latest available key.
-  void UpdateDesiredEncryptionKey(const std::string& name);
 
   // Applies a local deletion to this item.
   void Delete();
@@ -111,8 +104,7 @@
   // reached the server.
   void ReceiveCommitResponse(const std::string& id,
                              int64 sequence_number,
-                             int64 response_version,
-                             const std::string& encryption_key_name);
+                             int64 response_version);
 
   // Clears any in-memory sync state associated with outstanding commits.
   void ClearTransientSyncState();
@@ -132,8 +124,7 @@
                   const sync_pb::EntitySpecifics& specifics,
                   bool deleted,
                   base::Time ctime,
-                  base::Time mtime,
-                  const std::string& encryption_key_name);
+                  base::Time mtime);
 
   // A sequence number used to track in-progress commits.  Each local change
   // increments this number.
@@ -194,10 +185,6 @@
   // doesn't bother to inspect their values.
   base::Time ctime_;
   base::Time mtime_;
-
-  // The name of the encryption key used to encrypt this item on the server.
-  // Empty when no encryption is in use.
-  std::string encryption_key_name_;
 };
 
 }  // namespace syncer