[Sync] Have SBH tell SyncManager which types to purge

chrome/browser/sync/glue/sync_backend_host_unittest.cc

 // 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.
 
 #include "chrome/browser/sync/glue/sync_backend_host.h"
 
 #include <cstddef>
 
 #include "base/location.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 673 matching lines @@
   syncer::ModelTypeSet new_types(syncer::EXPERIMENTS, syncer::DEVICE_INFO);
   syncer::ModelTypeSet old_types =
       Difference(enabled_types_, new_types);
   fake_manager_factory_.set_progress_marker_types(old_types);
   fake_manager_factory_.set_initial_sync_ended_types(old_types);
 
   // Bringing up the backend should download the new types without downloading
   // any old types.
   InitializeBackend(true);
   EXPECT_TRUE(fake_manager_->GetAndResetDownloadedTypes().Equals(new_types));
-  EXPECT_TRUE(Intersection(fake_manager_->GetAndResetCleanedTypes(),
-                           enabled_types_).Empty());
+  EXPECT_TRUE(fake_manager_->GetAndResetCleanedTypes().Equals(
+                  Difference(syncer::ModelTypeSet::All(),
+                             enabled_types_)));
   EXPECT_TRUE(fake_manager_->InitialSyncEndedTypes().Equals(enabled_types_));
   EXPECT_TRUE(fake_manager_->GetTypesWithEmptyProgressMarkerToken(
       enabled_types_).Empty());
 }
 
 // Fail to download control types.  It's believed that there is a server bug
 // which can allow this to happen (crbug.com/164288).  The sync backend host
 // should detect this condition and fail to initialize the backend.
 //
 // The failure is "silent" in the sense that the GetUpdates request appears to
@@ skipping 56 matching lines @@
 TEST_F(SyncBackendHostTest, DownloadControlTypesRestart) {
   sync_prefs_->SetSyncSetupCompleted();
   InitializeBackend(true);
   EXPECT_EQ(syncer::CONFIGURE_REASON_NEWLY_ENABLED_DATA_TYPE,
             fake_manager_->GetAndResetConfigureReason());
 }
 
 }  // namespace
 
 }  // namespace browser_sync