Add Store+Sync to reading list.

ios/chrome/browser/sync/ios_chrome_sync_client.mm

Index: ios/chrome/browser/sync/ios_chrome_sync_client.mm
diff --git a/ios/chrome/browser/sync/ios_chrome_sync_client.mm b/ios/chrome/browser/sync/ios_chrome_sync_client.mm
index dfaa916d75f5301cdbdd0c662f79d0f5047c0473..46955fa63a9b9bbf77abd1849f65f313c02a8d74 100644
--- a/ios/chrome/browser/sync/ios_chrome_sync_client.mm
+++ b/ios/chrome/browser/sync/ios_chrome_sync_client.mm
@@ -52,6 +52,8 @@
 #include "ios/chrome/browser/invalidation/ios_chrome_profile_invalidation_provider_factory.h"
 #include "ios/chrome/browser/passwords/ios_chrome_password_store_factory.h"
 #include "ios/chrome/browser/pref_names.h"
+#include "ios/chrome/browser/reading_list/reading_list_model.h"
+#include "ios/chrome/browser/reading_list/reading_list_model_factory.h"
 #include "ios/chrome/browser/signin/oauth2_token_service_factory.h"
 #include "ios/chrome/browser/sync/glue/sync_start_util.h"
 #include "ios/chrome/browser/sync/ios_chrome_profile_sync_service_factory.h"
@@ -335,6 +337,13 @@ IOSChromeSyncClient::GetModelTypeServiceForType(syncer::ModelType type) {
                  browser_state_)
           ->GetDeviceInfoService()
           ->AsWeakPtr();
+    case syncer::READING_LIST: {
+      ReadingListModel* reading_list_model =
+          ReadingListModelFactory::GetForBrowserState(browser_state_);
+      if (reading_list_model)
+        return reading_list_model->GetModelTypeService()->AsWeakPtr();
+      return base::WeakPtr<syncer::ModelTypeService>();
+    }
     default:
       NOTREACHED();
       return base::WeakPtr<syncer::ModelTypeService>();