sync: Add non-blocking type encryption support

sync/internal_api/public/non_blocking_sync_common.h

Index: sync/internal_api/public/non_blocking_sync_common.h
diff --git a/sync/internal_api/public/non_blocking_sync_common.h b/sync/internal_api/public/non_blocking_sync_common.h
index 7c7580bb53521718cdf9527a34f0df92f8600ba4..0ef71b4a0771ef5726f9ee4bb77791ab87f5d91c 100644
--- a/sync/internal_api/public/non_blocking_sync_common.h
+++ b/sync/internal_api/public/non_blocking_sync_common.h
@@ -16,42 +16,6 @@ namespace syncer {
 
 static const int64 kUncommittedVersion = -1;
 
-// Data-type global state that must be accessed and updated on the sync thread,
-// but persisted on or through the model thread.
-struct SYNC_EXPORT_PRIVATE DataTypeState {
-  DataTypeState();
-  ~DataTypeState();
-
-  // The latest progress markers received from the server.
-  sync_pb::DataTypeProgressMarker progress_marker;
-
-  // A data type context.  Sent to the server in every commit or update
-  // request.  May be updated by either by responses from the server or
-  // requests made on the model thread.  The interpretation of this value may
-  // be data-type specific.  Many data types ignore it.
-  sync_pb::DataTypeContext type_context;
-
-  // The ID of the folder node that sits at the top of this type's folder
-  // hierarchy.  We keep this around for legacy reasons.  The protocol expects
-  // that all nodes of a certain type are children of the same type root
-  // entity.  This entity is delivered by the server, and may not be available
-  // until the first download cycle has completed.
-  std::string type_root_id;
-
-  // A strictly increasing counter used to generate unique values for the
-  // client-assigned IDs.  The incrementing and ID assignment happens on the
-  // sync thread, but we store the value here so we can pass it back to the
-  // model thread for persistence.  This is probably unnecessary for the
-  // client-tagged data types supported by non-blocking sync, but we will
-  // continue to emulate the directory sync's behavior for now.
-  int64 next_client_id;
-
-  // This flag is set to true when the first download cycle is complete.  The
-  // ModelTypeSyncProxy should not attempt to commit any items until this
-  // flag is set.
-  bool initial_sync_done;
-};
-
 struct SYNC_EXPORT_PRIVATE CommitRequestData {
   CommitRequestData();
   ~CommitRequestData();
@@ -94,12 +58,54 @@ struct SYNC_EXPORT_PRIVATE UpdateResponseData {
   std::string non_unique_name;
   bool deleted;
   sync_pb::EntitySpecifics specifics;
+  std::string encryption_key_name;
 };
 
 typedef std::vector<CommitRequestData> CommitRequestDataList;
 typedef std::vector<CommitResponseData> CommitResponseDataList;
 typedef std::vector<UpdateResponseData> UpdateResponseDataList;
 
+// Data-type global state that must be accessed and updated on the sync thread,
+// but persisted on or through the model thread.
+struct SYNC_EXPORT_PRIVATE DataTypeState {
+  DataTypeState();
+  ~DataTypeState();
+
+  // The latest progress markers received from the server.
+  sync_pb::DataTypeProgressMarker progress_marker;
+
+  // A data type context.  Sent to the server in every commit or update
+  // request.  May be updated by either by responses from the server or
+  // requests made on the model thread.  The interpretation of this value may
+  // be data-type specific.  Many data types ignore it.
+  sync_pb::DataTypeContext type_context;
+
+  // The ID of the folder node that sits at the top of this type's folder
+  // hierarchy.  We keep this around for legacy reasons.  The protocol expects
+  // that all nodes of a certain type are children of the same type root
+  // entity.  This entity is delivered by the server, and may not be available
+  // until the first download cycle has completed.
+  std::string type_root_id;
+
+  // This value is set if this type's data should be encrypted on the server.
+  // If this key changes, the client will need to re-commit all of its local
+  // data to the server using the new encryption key.
+  std::string encryption_key_name;
+
+  // A strictly increasing counter used to generate unique values for the
+  // client-assigned IDs.  The incrementing and ID assignment happens on the
+  // sync thread, but we store the value here so we can pass it back to the
+  // model thread for persistence.  This is probably unnecessary for the
+  // client-tagged data types supported by non-blocking sync, but we will
+  // continue to emulate the directory sync's behavior for now.
+  int64 next_client_id;
+
+  // This flag is set to true when the first download cycle is complete.  The
+  // ModelTypeSyncProxy should not attempt to commit any items until this
+  // flag is set.
+  bool initial_sync_done;
+};
+
 }  // namespace syncer
 
 #endif  // SYNC_INTERNAL_API_PUBLIC_NON_BLOCKING_SYNC_COMMON_H_