[Sync] rename USS processor / worker interfaces

sync/engine/entity_tracker_unittest.cc

Index: sync/engine/entity_tracker_unittest.cc
diff --git a/sync/engine/entity_tracker_unittest.cc b/sync/engine/entity_tracker_unittest.cc
index b814d79e6132136a4626b37c85a8a5ac6a7f72b2..4356afac4e43fa344681136f1108a8af1335675f 100644
--- a/sync/engine/entity_tracker_unittest.cc
+++ b/sync/engine/entity_tracker_unittest.cc
@@ -16,9 +16,9 @@ namespace syncer_v2 {
 
 // Some simple tests for the EntityTracker.
 //
-// The EntityTracker is an implementation detail of the ModelTypeSyncWorker.
+// The EntityTracker is an implementation detail of the CommitQueue.
 // As such, it doesn't make much sense to test it exhaustively, since it
-// already gets a lot of test coverage from the ModelTypeSyncWorker unit tests.
+// already gets a lot of test coverage from the CommitQueue unit tests.
 //
 // These tests are intended as a basic sanity check.  Anything more complicated
 // would be redundant.