Remove single direction conflict set code

chrome/browser/sync/sessions/session_state.h

 // 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.
 
 // The 'sessions' namespace comprises all the pieces of state that are
 // combined to form a SyncSession instance. In that way, it can be thought of
 // as an extension of the SyncSession type itself. Session scoping gives
 // context to things like "conflict progress", "update progress", etc, and the
 // separation this file provides allows clients to only include the parts they
 // need rather than the entire session stack.
@@ skipping 240 matching lines @@
  private:
   // Container for updates that passed verification.
   std::vector<VerifiedUpdate> verified_updates_;
 
   // Stores the result of the various ApplyUpdate attempts we've made.
   // May contain duplicate entries.
   std::vector<AppliedUpdate> applied_updates_;
 };
 
 struct SyncCycleControlParameters {
-  SyncCycleControlParameters() : conflict_sets_built(false),
-                                 conflicts_resolved(false),
+  SyncCycleControlParameters() : conflicts_resolved(false),
                                  items_committed(false),
                                  debug_info_sent(false) {}
-  // Set to true by BuildAndProcessConflictSetsCommand if the RESOLVE_CONFLICTS
-  // step is needed.
-  bool conflict_sets_built;
-
   // Set to true by ResolveConflictsCommand if any forward progress was made.
   bool conflicts_resolved;
 
   // Set to true by PostCommitMessageCommand if any commits were successful.
   bool items_committed;
 
   // True indicates debug info has been sent once this session.
   bool debug_info_sent;
 };
 
@@ skipping 51 matching lines @@
   ~PerModelSafeGroupState();
 
   UpdateProgress update_progress;
   ConflictProgress conflict_progress;
 };
 
 }  // namespace sessions
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_SESSIONS_SESSION_STATE_H_