[Sync] Move sessions/ to engine/cycle/ and rename things to match.

components/sync/protocol/client_debug_info.proto

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // Sync protocol for debug info clients can send to the sync server.
 
 syntax = "proto2";
 
 option optimize_for = LITE_RUNTIME;
 option retain_unknown_fields = true;
@@ skipping 40 matching lines @@
   optional int32 num_encryption_conflicts = 4;
   optional int32 num_hierarchy_conflicts = 5;
   optional int32 num_simple_conflicts = 6;  // No longer sent since M24.
   optional int32 num_server_conflicts = 7;
 
   // Counts to track the effective usefulness of our GetUpdate requests.
   optional int32 num_updates_downloaded = 8;
   optional int32 num_reflected_updates_downloaded = 9;
   optional GetUpdatesCallerInfo caller_info = 10;
 
-  // A list of all the sources that were merged into this session.
+  // A list of all the sources that were merged into this cycle.
   //
   // Some scenarios, notably mode switches and canary jobs, can spuriously add
   // back-to-back duplicate sources to this list.
   repeated SourceInfo source_info = 11;
 }
 
 // Datatype specifics statistics gathered at association time.
 message DatatypeAssociationStats {
   // The datatype that was associated.
   optional int32 data_type_id = 1;
 
   // The state of the world before association.
   optional int32 num_local_items_before_association = 2;
   optional int32 num_sync_items_before_association = 3;
 
   // The state of the world after association.
   optional int32 num_local_items_after_association = 4;
   optional int32 num_sync_items_after_association = 5;
 
   // The changes that got us from before to after. In a correctly working
   // system these should be the deltas between before and after.
   optional int32 num_local_items_added = 6;
   optional int32 num_local_items_deleted = 7;
   optional int32 num_local_items_modified = 8;
   optional int32 num_sync_items_added = 9;
   optional int32 num_sync_items_deleted = 10;
   optional int32 num_sync_items_modified = 11;
 
   // Model versions before association. Ideally local and sync model should
-  // have same version if models were persisted properly in last session.
+  // have same version if models were persisted properly in last cycle.
   // Note: currently version is only set on bookmark model.
   optional int64 local_version_pre_association = 20;
   optional int64 sync_version_pre_association = 21;
 
   // The data type ran into an error during model association.
   optional bool had_error = 12;
 
   // Waiting time before downloading starts. This measures the time between
   // receiving configuration request for a set of data types to starting
   // downloading data of this type.
@@ skipping 55 matching lines @@
   // Whether cryptographer is ready to encrypt and decrypt data.
   optional bool cryptographer_ready = 2;
 
   // Cryptographer has pending keys which indicates the correct passphrase
   // has not been provided yet.
   optional bool cryptographer_has_pending_keys = 3;
 
   // Indicates client has dropped some events to save bandwidth.
   optional bool events_dropped = 4;
 }