Avoid re-starting a ExternalCCResultFetcher if a previous has finished or timed out.

components/signin/core/browser/gaia_cookie_manager_service.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/signin/core/browser/gaia_cookie_manager_service.h"
 
 #include <stddef.h>
 
 #include <queue>
 
@@ skipping 266 matching lines @@
   base::TimeDelta time_to_check_connections =
       base::Time::Now() - m_external_cc_result_start_time_;
   signin_metrics::LogExternalCcResultFetches(succeeded,
                                              time_to_check_connections);
 
   helper_->external_cc_result_fetched_ = true;
   // Since the ExternalCCResultFetcher is only Started in place of calling
   // StartFetchingMergeSession, we can assume we need to call
   // StartFetchingMergeSession. If this assumption becomes invalid, a Callback
   // will need to be passed to Start() and Run() here.
-  helper_->StartFetchingMergeSession();
+  if (!helper_->uber_token_.empty())
+    helper_->StartFetchingMergeSession();

[Roger Tawa OOO till Jul 10th, 2017/02/21 16:15:16]

I wonder if you need to explicitly call OnMergeSessionFailure() in this case to
make sure pending requests are still handled.  Does that make sense?

[msarda, 2017/02/23 17:29:22]

After you reply, I've debugged this more carefully. I have updated the CL
description and went for a different fix.

 }
 
 GaiaCookieManagerService::GaiaCookieManagerService(
     OAuth2TokenService* token_service,
     const std::string& source,
     SigninClient* signin_client)
     : token_service_(token_service),
       signin_client_(signin_client),
       external_cc_result_fetcher_(this),
       fetcher_backoff_(&kBackoffPolicy),
@@ skipping 496 matching lines @@
         break;
       case GaiaCookieRequestType::LIST_ACCOUNTS:
         uber_token_fetcher_.reset();
         signin_client_->DelayNetworkCall(
             base::Bind(&GaiaCookieManagerService::StartFetchingListAccounts,
                        base::Unretained(this)));
         break;
     }
   }
 }