Allow signin to continue even if sync is disabled by policy.

chrome/browser/profiles/profile_impl.cc

Index: chrome/browser/profiles/profile_impl.cc
diff --git a/chrome/browser/profiles/profile_impl.cc b/chrome/browser/profiles/profile_impl.cc
index 46dbd95c943a9d32d8314e3d1e69c72161d861c4..855c5563e626db4fb1f71c05368f811e6895b55f 100644
--- a/chrome/browser/profiles/profile_impl.cc
+++ b/chrome/browser/profiles/profile_impl.cc
@@ -881,6 +881,13 @@ net::URLRequestContextGetter* ProfileImpl::GetRequestContextForStoragePartition(
 }
 
 net::SSLConfigService* ProfileImpl::GetSSLConfigService() {
+  // If ssl_config_service_manager_ is null, this typically means that some
+  // ProfileKeyedService is trying to create a RequestContext at startup, but
+  // SSLConfigServiceManager is not initialized until DoFinalInit() which is
+  // invoked after all ProfileKeyedServices have been initialized (see
+  // http://crbug.com/171406).
+  DCHECK(ssl_config_service_manager_.get()) <<
+      "SSLConfigServiceManager is not initialized yet";
   return ssl_config_service_manager_->Get();
 }