Revert of sync: Add non-blocking type encryption support

sync/engine/model_type_entity.cc

Index: sync/engine/model_type_entity.cc
diff --git a/sync/engine/model_type_entity.cc b/sync/engine/model_type_entity.cc
index 2f758a8e4d64379499635daedc8eaa1e3bac5ae1..5acf5db48138795c81a57bd050d58ae2dd13c58c 100644
--- a/sync/engine/model_type_entity.cc
+++ b/sync/engine/model_type_entity.cc
@@ -24,8 +24,7 @@
       specifics,
       false,
       now,
-      now,
-      std::string()));
+      now));
 }
 
 scoped_ptr<ModelTypeEntity> ModelTypeEntity::FromServerUpdate(
@@ -36,8 +35,7 @@
     const sync_pb::EntitySpecifics& specifics,
     bool deleted,
     base::Time ctime,
-    base::Time mtime,
-    const std::string& encryption_key_name) {
+    base::Time mtime) {
   return scoped_ptr<ModelTypeEntity>(new ModelTypeEntity(0,
                                                          0,
                                                          0,
@@ -49,8 +47,7 @@
                                                          specifics,
                                                          deleted,
                                                          ctime,
-                                                         mtime,
-                                                         encryption_key_name));
+                                                         mtime));
 }
 
 ModelTypeEntity::ModelTypeEntity(int64 sequence_number,
@@ -64,8 +61,7 @@
                                  const sync_pb::EntitySpecifics& specifics,
                                  bool deleted,
                                  base::Time ctime,
-                                 base::Time mtime,
-                                 const std::string& encryption_key_name)
+                                 base::Time mtime)
     : sequence_number_(sequence_number),
       commit_requested_sequence_number_(commit_requested_sequence_number),
       acked_sequence_number_(acked_sequence_number),
@@ -77,8 +73,7 @@
       specifics_(specifics),
       deleted_(deleted),
       ctime_(ctime),
-      mtime_(mtime),
-      encryption_key_name_(encryption_key_name) {
+      mtime_(mtime) {
 }
 
 ModelTypeEntity::~ModelTypeEntity() {
@@ -108,8 +103,7 @@
     int64 update_version,
     bool deleted,
     const sync_pb::EntitySpecifics& specifics,
-    base::Time mtime,
-    const std::string& encryption_key_name) {
+    base::Time mtime) {
   // There was a conflict and the server just won it.
   // This implicitly acks all outstanding commits because a received update
   // will clobber any pending commits on the sync thread.
@@ -125,15 +119,6 @@
     const sync_pb::EntitySpecifics& specifics) {
   sequence_number_++;
   specifics_ = specifics;
-}
-
-void ModelTypeEntity::UpdateDesiredEncryptionKey(const std::string& name) {
-  if (encryption_key_name_ == name)
-    return;
-
-  // Schedule commit with the expectation that the worker will re-encrypt with
-  // the latest encryption key as it does.
-  sequence_number_++;
 }
 
 void ModelTypeEntity::Delete() {
@@ -159,15 +144,12 @@
   commit_requested_sequence_number_ = sequence_number_;
 }
 
-void ModelTypeEntity::ReceiveCommitResponse(
-    const std::string& id,
-    int64 sequence_number,
-    int64 response_version,
-    const std::string& encryption_key_name) {
+void ModelTypeEntity::ReceiveCommitResponse(const std::string& id,
+                                            int64 sequence_number,
+                                            int64 response_version) {
   id_ = id;  // The server can assign us a new ID in a commit response.
   acked_sequence_number_ = sequence_number;
   base_version_ = response_version;
-  encryption_key_name_ = encryption_key_name;
 }
 
 void ModelTypeEntity::ClearTransientSyncState() {