Merge 65225 - Crash fix: HTTPS server responds with 407 through non-authentic...

net/http/http_network_transaction.cc

Index: net/http/http_network_transaction.cc
===================================================================
--- net/http/http_network_transaction.cc	(revision 65244)
+++ net/http/http_network_transaction.cc	(working copy)
@@ -1183,6 +1183,11 @@
   if (target == HttpAuth::AUTH_PROXY && proxy_info_.is_direct())
     return ERR_UNEXPECTED_PROXY_AUTH;
 
+  // This case can trigger when an HTTPS server responds with a 407 status
+  // code through a non-authenticating proxy.
+  if (!auth_controllers_[target].get())
+    return ERR_UNEXPECTED_PROXY_AUTH;
+
   int rv = auth_controllers_[target]->HandleAuthChallenge(
       headers, (request_->load_flags & LOAD_DO_NOT_SEND_AUTH_DATA) != 0, false,
       net_log_);