[Sync] SyncEngine 1.5: Fix all backend references in PSS.

components/sync/driver/glue/sync_backend_host_impl.cc

Index: components/sync/driver/glue/sync_backend_host_impl.cc
diff --git a/components/sync/driver/glue/sync_backend_host_impl.cc b/components/sync/driver/glue/sync_backend_host_impl.cc
index b276ae221ec4fd5d30cd61a1043c3ffca9eb42fc..77be61bda6d654fe39f79aaf09c9deb61115fe4a 100644
--- a/components/sync/driver/glue/sync_backend_host_impl.cc
+++ b/components/sync/driver/glue/sync_backend_host_impl.cc
@@ -562,15 +562,14 @@ void SyncBackendHostImpl::HandleInitializationSuccessOnFrontendLoop(
   // experimental types to enable. This should be done before we inform
   // the host to ensure they're visible in the customize screen.
   AddExperimentalTypes();
-  host_->OnBackendInitialized(js_backend, debug_info_listener, cache_guid,
-                              true);
+  host_->OnEngineInitialized(js_backend, debug_info_listener, cache_guid, true);
 }
 
 void SyncBackendHostImpl::HandleInitializationFailureOnFrontendLoop() {
   DCHECK(thread_checker_.CalledOnValidThread());
-  host_->OnBackendInitialized(WeakHandle<JsBackend>(),
-                              WeakHandle<DataTypeDebugInfoListener>(), "",
-                              false);
+  host_->OnEngineInitialized(WeakHandle<JsBackend>(),
+                             WeakHandle<DataTypeDebugInfoListener>(), "",
+                             false);
 }
 
 void SyncBackendHostImpl::HandleSyncCycleCompletedOnFrontendLoop(