[Sync] Plumb initial type set from engine to DTM.

components/sync/driver/glue/sync_backend_host_impl.cc

 // Copyright 2013 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 "components/sync/driver/glue/sync_backend_host_impl.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 521 matching lines @@
 }
 
 void SyncBackendHostImpl::AddExperimentalTypes() {
   CHECK(initialized());
   Experiments experiments;
   if (core_->sync_manager()->ReceivedExperiment(&experiments))
     host_->OnExperimentsChanged(experiments);
 }
 
 void SyncBackendHostImpl::HandleInitializationSuccessOnFrontendLoop(
+    ModelTypeSet initial_types,
     const WeakHandle<JsBackend> js_backend,
     const WeakHandle<DataTypeDebugInfoListener> debug_info_listener,
     std::unique_ptr<ModelTypeConnector> model_type_connector,
     const std::string& cache_guid) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   model_type_connector_ = std::move(model_type_connector);
 
   initialized_ = true;
 
   if (invalidator_) {
     invalidator_->RegisterInvalidationHandler(this);
     invalidation_handler_registered_ = true;
 
     // Fake a state change to initialize the SyncManager's cached invalidator
     // state.
     OnInvalidatorStateChange(invalidator_->GetInvalidatorState());
   }
 
   // Now that we've downloaded the control types, we can see if there are any
   // experimental types to enable. This should be done before we inform
   // the host to ensure they're visible in the customize screen.
   AddExperimentalTypes();
-  host_->OnEngineInitialized(js_backend, debug_info_listener, cache_guid, true);
+  host_->OnEngineInitialized(initial_types, js_backend, debug_info_listener,
+                             cache_guid, true);
 }
 
 void SyncBackendHostImpl::HandleInitializationFailureOnFrontendLoop() {
   DCHECK(thread_checker_.CalledOnValidThread());
-  host_->OnEngineInitialized(WeakHandle<JsBackend>(),
+  host_->OnEngineInitialized(ModelTypeSet(), WeakHandle<JsBackend>(),
                              WeakHandle<DataTypeDebugInfoListener>(), "",
                              false);
 }
 
 void SyncBackendHostImpl::HandleSyncCycleCompletedOnFrontendLoop(
     const SyncCycleSnapshot& snapshot) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   last_snapshot_ = snapshot;
 
@@ skipping 180 matching lines @@
     const SyncManager::ClearServerDataCallback& frontend_callback) {
   DCHECK(thread_checker_.CalledOnValidThread());
   frontend_callback.Run();
 }
 
 }  // namespace syncer
 
 #undef SDVLOG
 
 #undef SLOG