sync: raise initial backoff interval from 1 second to 5 minutes.

sync/internal_api/public/engine/polling_constants.cc

 // Copyright (c) 2012 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 "base/basictypes.h"
 #include "sync/internal_api/public/engine/polling_constants.h"
 
 namespace syncer {
 
 // Server can overwrite these values via client commands.
 // Standard short poll. This is used when XMPP is off.
 // We use high values here to ensure that failure to receive poll updates from
 // the server doesn't result in rapid-fire polling from the client due to low
 // local limits.
 const int64 kDefaultShortPollIntervalSeconds = 3600 * 8;
 // Long poll is used when XMPP is on.
 const int64 kDefaultLongPollIntervalSeconds = 3600 * 12;
 
 // Maximum interval for exponential backoff.
 const int64 kMaxBackoffSeconds = 60 * 60 * 4;  // 4 hours.
 
 // Backoff interval randomization factor.
 const int kBackoffRandomizationFactor = 2;
 
+// After a failure contacting sync servers, specifies how long to wait before
+// reattempting and entering exponential backoff if consecutive failures
+// occur.
+const int kInitialBackoffRetrySeconds = 60 * 5;  // 5 minutes.
+
+// Similar to kInitialBackoffRetrySeconds above, but only to be used in
+// certain exceptional error cases, such as MIGRATION_DONE.
+const int kInitialBackoffShortRetrySeconds = 1;
+
 }  // namespace syncer
-