Only verify token during Profile creation.

After Profile creation, there is no need to re-check token because cloud
policy has been loaded already.

Bug: 936525
Change-Id: I53f81ea35cd70ba9b7255046e955de78b8103e27
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1494800Reviewed-by: David Roger <droger@chromium.org>
Commit-Queue: Owen Min <zmin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#638143}

chrome/browser/signin/chrome_signin_client.cc

@@ -303,7 +303,8 @@ std::unique_ptr<GaiaAuthFetcher> ChromeSigninClient::CreateGaiaAuthFetcher(
 
 void ChromeSigninClient::VerifySyncToken() {
 #if !defined(OS_ANDROID) && !defined(OS_CHROMEOS)
-  if (signin_util::IsForceSigninEnabled())
+  // We only verifiy the token once when Profile is just created.
+  if (signin_util::IsForceSigninEnabled() && !force_signin_verifier_)
     force_signin_verifier_ = std::make_unique<ForceSigninVerifier>(profile_);
 #endif
 }