[Sync] Add support for performing a GetKey on startup.

chrome/browser/sync/glue/sync_backend_host.cc

Index: chrome/browser/sync/glue/sync_backend_host.cc
diff --git a/chrome/browser/sync/glue/sync_backend_host.cc b/chrome/browser/sync/glue/sync_backend_host.cc
index 206773525ca0e2aeb2069095ce3d93b190ece7a0..166432deca031c4d2981f3dc622a184f3f91e4d0 100644
--- a/chrome/browser/sync/glue/sync_backend_host.cc
+++ b/chrome/browser/sync/glue/sync_backend_host.cc
@@ -980,6 +980,8 @@ void SyncBackendHost::Core::DoInitialize(const DoInitializeOptions& options) {
           options.chrome_sync_notification_bridge,
           options.sync_notifier_factory->CreateSyncNotifier())),
       options.restored_key_for_bootstrapping,
+      CommandLine::ForCurrentProcess()->HasSwitch(
+              switches::kSyncKeystoreEncryption),
       options.testing_mode,
       &encryptor_,
       options.unrecoverable_error_handler,