[Sync] Have SBH tell SyncManager which types to purge

chrome/browser/sync/glue/sync_backend_registrar_unittest.cc

Index: chrome/browser/sync/glue/sync_backend_registrar_unittest.cc
diff --git a/chrome/browser/sync/glue/sync_backend_registrar_unittest.cc b/chrome/browser/sync/glue/sync_backend_registrar_unittest.cc
index 3761067e8f8f7fc0d3ffdad3d8471df9fb4adb13..979f9a5a3f2a5633eb321fd1b0da053415222124 100644
--- a/chrome/browser/sync/glue/sync_backend_registrar_unittest.cc
+++ b/chrome/browser/sync/glue/sync_backend_registrar_unittest.cc
@@ -128,6 +128,7 @@ TEST_F(SyncBackendRegistrarTest, ConfigureDataTypes) {
     ExpectRoutingInfo(&registrar, expected_routing_info);
   }
   ExpectHasProcessorsForTypes(registrar, ModelTypeSet());
+  EXPECT_TRUE(types1.Equals(registrar.GetLastConfiguredTypes()));
 
   // Add and remove.
   const ModelTypeSet types2(PREFERENCES, THEMES);
@@ -139,11 +140,13 @@ TEST_F(SyncBackendRegistrarTest, ConfigureDataTypes) {
     ExpectRoutingInfo(&registrar, expected_routing_info);
   }
   ExpectHasProcessorsForTypes(registrar, ModelTypeSet());
+  EXPECT_TRUE(types2.Equals(registrar.GetLastConfiguredTypes()));
 
   // Remove.
   EXPECT_TRUE(registrar.ConfigureDataTypes(ModelTypeSet(), types2).Empty());
   ExpectRoutingInfo(&registrar, syncer::ModelSafeRoutingInfo());
   ExpectHasProcessorsForTypes(registrar, ModelTypeSet());
+  EXPECT_TRUE(ModelTypeSet().Equals(registrar.GetLastConfiguredTypes()));
 
   registrar.OnSyncerShutdownComplete();
   registrar.StopOnUIThread();