Disable account consistency.

//ios/web_view does not need to mirror accounts.

Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: I100f3005dd3d02dd03c5f8e730e4ce3daa492d62
Reviewed-on: https://chromium-review.googlesource.com/1142543Reviewed-by: Hiroshi Ichikawa <ichikawa@chromium.org>
Commit-Queue: John Wu <jzw@chromium.org>
Cr-Commit-Position: refs/heads/master@{#576372}

ios/web_view/internal/signin/web_view_signin_manager_factory.mm

@@ -75,7 +75,7 @@ WebViewSigninManagerFactory::BuildServiceInstanceFor(
       WebViewAccountTrackerServiceFactory::GetForBrowserState(browser_state),
       WebViewGaiaCookieManagerServiceFactory::GetForBrowserState(browser_state),
       WebViewSigninErrorControllerFactory::GetForBrowserState(browser_state),
-      signin::AccountConsistencyMethod::kMirror);
+      signin::AccountConsistencyMethod::kDisabled);
   service->Initialize(ApplicationContext::GetInstance()->GetLocalState());
   return service;
 }