[Sync] Have SBH tell SyncManager which types to purge

chrome/browser/sync/glue/sync_backend_registrar.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_registrar.h"
 
 #include <cstddef>
 
 #include "base/compiler_specific.h"
 #include "base/logging.h"
@@ skipping 67 matching lines @@
   }
 
   scoped_refptr<PasswordStore> password_store =
       PasswordStoreFactory::GetForProfile(profile, Profile::IMPLICIT_ACCESS);
   if (password_store.get()) {
     workers_[syncer::GROUP_PASSWORD] =
         new PasswordModelWorker(password_store, this);
   }
 }
 
+SyncBackendRegistrar::~SyncBackendRegistrar() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DCHECK(stopped_on_ui_thread_);
+}
+
 void SyncBackendRegistrar::SetInitialTypes(syncer::ModelTypeSet initial_types) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   base::AutoLock lock(lock_);
 
   // This function should be called only once, shortly after construction.  The
   // routing info at that point is expected to be emtpy.
   DCHECK(routing_info_.empty());
 
   // Set our initial state to reflect the current status of the sync directory.
   // This will ensure that our calculations in ConfigureDataTypes() will always
   // return correct results.
   for (syncer::ModelTypeSet::Iterator it = initial_types.First();
        it.Good(); it.Inc()) {
     routing_info_[it.Get()] = syncer::GROUP_PASSIVE;
   }
 
   if (!workers_.count(syncer::GROUP_HISTORY)) {
     LOG_IF(WARNING, initial_types.Has(syncer::TYPED_URLS))
         << "History store disabled, cannot sync Omnibox History";
     routing_info_.erase(syncer::TYPED_URLS);
   }
 
   if (!workers_.count(syncer::GROUP_PASSWORD)) {
     LOG_IF(WARNING, initial_types.Has(syncer::PASSWORDS))
         << "Password store not initialized, cannot sync passwords";
     routing_info_.erase(syncer::PASSWORDS);
   }
-}
 
-SyncBackendRegistrar::~SyncBackendRegistrar() {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  DCHECK(stopped_on_ui_thread_);
+  last_configured_types_ = syncer::GetRoutingInfoTypes(routing_info_);
 }
 
 bool SyncBackendRegistrar::IsNigoriEnabled() const {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   base::AutoLock lock(lock_);
   return routing_info_.find(syncer::NIGORI) != routing_info_.end();
 }
 
 syncer::ModelTypeSet SyncBackendRegistrar::ConfigureDataTypes(
     syncer::ModelTypeSet types_to_add,
@@ skipping 28 matching lines @@
 
   // TODO(akalin): Use SVLOG/SLOG if we add any more logging.
   DVLOG(1) << name_ << ": Adding types "
            << syncer::ModelTypeSetToString(types_to_add)
            << " (with newly-added types "
            << syncer::ModelTypeSetToString(newly_added_types)
            << ") and removing types "
            << syncer::ModelTypeSetToString(types_to_remove)
            << " to get new routing info "
            <<syncer::ModelSafeRoutingInfoToString(routing_info_);
+  last_configured_types_ = syncer::GetRoutingInfoTypes(routing_info_);
 
   return newly_added_types;
 }
 
+syncer::ModelTypeSet SyncBackendRegistrar::GetLastConfiguredTypes() const {
+  return last_configured_types_;
+}
+
 void SyncBackendRegistrar::StopOnUIThread() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DCHECK(!stopped_on_ui_thread_);
   ui_worker_->Stop();
   stopped_on_ui_thread_ = true;
 }
 
 void SyncBackendRegistrar::OnSyncerShutdownComplete() {
   DCHECK_EQ(base::MessageLoop::current(), sync_loop_);
   ui_worker_->OnSyncerShutdownComplete();
@@ skipping 113 matching lines @@
   lock_.AssertAcquired();
   return IsOnThreadForGroup(model_type,
                             GetGroupForModelType(model_type, routing_info_));
 }
 
 void SyncBackendRegistrar::OnWorkerLoopDestroyed(syncer::ModelSafeGroup group) {
   // Do nothing for now.
 }
 
 }  // namespace browser_sync