Revert of [Sync] Adds a new switch for enabling the new local server backend.

components/sync/engine_impl/sync_manager_impl.cc

Index: components/sync/engine_impl/sync_manager_impl.cc
diff --git a/components/sync/engine_impl/sync_manager_impl.cc b/components/sync/engine_impl/sync_manager_impl.cc
index 06720a0318cd330c99eae2c460fe70087c2c9989..f0b7cada4332de19b27870ea39136655e47e80f2 100644
--- a/components/sync/engine_impl/sync_manager_impl.cc
+++ b/components/sync/engine_impl/sync_manager_impl.cc
@@ -47,10 +47,6 @@
 #include "components/sync/syncable/write_node.h"
 #include "components/sync/syncable/write_transaction.h"
 
-#if defined(OS_WIN)
-#include "components/sync/engine_impl/loopback_server/loopback_connection_manager.h"
-#endif
-
 using base::TimeDelta;
 using sync_pb::GetUpdatesCallerInfo;
 
@@ -286,21 +282,11 @@
     args->saved_nigori_state.reset();
   }
 
-  if (args->enable_local_sync_backend) {
-#if defined(OS_WIN)
-    VLOG(1) << "Running against local sync backend.";
-    connection_manager_ = base::MakeUnique<LoopbackConnectionManager>(
-        args->cancelation_signal, args->local_sync_backend_folder);
-#else
-    NOTREACHED();
-#endif  // defined(OS_WIN)
-  } else {
-    connection_manager_ = base::MakeUnique<SyncServerConnectionManager>(
-        args->service_url.host() + args->service_url.path(),
-        args->service_url.EffectiveIntPort(),
-        args->service_url.SchemeIsCryptographic(), args->post_factory.release(),
-        args->cancelation_signal);
-  }
+  connection_manager_ = base::MakeUnique<SyncServerConnectionManager>(
+      args->service_url.host() + args->service_url.path(),
+      args->service_url.EffectiveIntPort(),
+      args->service_url.SchemeIsCryptographic(), args->post_factory.release(),
+      args->cancelation_signal);
   connection_manager_->set_client_id(directory()->cache_guid());
   connection_manager_->AddListener(this);