[Sync] Make syncer commands avoid posting tasks on threads with no work to do

chrome/browser/sync/sessions/status_controller.h

 // Copyright (c) 2011 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.
 
 // StatusController handles all counter and status related number crunching and
 // state tracking on behalf of a SyncSession.  It 'controls' the model data
 // defined in session_state.h.  The most important feature of StatusController
 // is the ScopedModelSafetyRestriction. When one of these is active, the
 // underlying data set exposed via accessors is swapped out to the appropriate
 // set for the restricted ModelSafeGroup behind the scenes.  For example, if
@@ skipping 45 matching lines @@
 
   // Progress counters.  All const methods may return NULL if the
   // progress structure doesn't exist, but all non-const methods
   // auto-create.
   const ConflictProgress* conflict_progress() const;
   ConflictProgress* mutable_conflict_progress();
   const UpdateProgress* update_progress() const;
   UpdateProgress* mutable_update_progress();
   const ConflictProgress* GetUnrestrictedConflictProgress(
       ModelSafeGroup group) const;
+  ConflictProgress* GetUnrestrictedMutableConflictProgressForTest(
+      ModelSafeGroup group);
   const UpdateProgress* GetUnrestrictedUpdateProgress(
       ModelSafeGroup group) const;
+  UpdateProgress* GetUnrestrictedMutableUpdateProgressForTest(
+      ModelSafeGroup group);
 
   // ClientToServer messages.
   const ClientToServerMessage& commit_message() {
     return shared_.commit_message;
   }
   ClientToServerMessage* mutable_commit_message() {
     return &shared_.commit_message;
   }
   const ClientToServerResponse& commit_response() const {
     return shared_.commit_response;
@@ skipping 213 matching lines @@
   }
  private:
   StatusController* status_;
   DISALLOW_COPY_AND_ASSIGN(ScopedModelSafeGroupRestriction);
 };
 
 }
 }
 
 #endif  // CHROME_BROWSER_SYNC_SESSIONS_STATUS_CONTROLLER_H_