[Sync] Sync should run canary cycle after any network related error

sync/engine/backoff_delay_provider.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 "sync/engine/backoff_delay_provider.h"
 
 #include <stdint.h>
 
 #include <algorithm>
 
@@ skipping 47 matching lines @@
 
   // Cap the backoff interval.
   backoff_s = std::max(static_cast<int64_t>(1),
                        std::min(backoff_s, kMaxBackoffSeconds));
 
   return TimeDelta::FromSeconds(backoff_s);
 }
 
 TimeDelta BackoffDelayProvider::GetInitialDelay(
     const sessions::ModelNeutralState& state) const {
-  // NETWORK_CONNECTION_UNAVAILABLE implies we did not even manage to hit the
-  // wire; the failure occurred locally. Note that if commit_result is *not*
-  // UNSET, this implies download_updates_result succeeded.  Also note that
-  // last_get_key_result is coupled to last_download_updates_result in that
-  // they are part of the same GetUpdates request, so we only check if
-  // the download request is CONNECTION_UNAVAILABLE.
-  //
-  // TODO(tim): Should we treat NETWORK_IO_ERROR similarly? It's different
-  // from CONNECTION_UNAVAILABLE in that a request may well have succeeded
-  // in contacting the server (e.g we got a 200 back), but we failed
-  // trying to parse the response (actual content length != HTTP response
-  // header content length value).  For now since we're considering
-  // merging this code to branches and I haven't audited all the
-  // NETWORK_IO_ERROR cases carefully, I'm going to target the fix
-  // very tightly (see bug chromium-os:35073). DIRECTORY_LOOKUP_FAILED is
-  // another example of something that shouldn't backoff, though the
-  // scheduler should probably be handling these cases differently. See
-  // the TODO(rlarocque) in ScheduleNextSync.
+  // NETWORK_CONNECTION_UNAVAILABLE implies we did not receive HTTP response
+  // from server because of some network error. If network is unavailable then
+  // on next connection type or address change scheduler will run canary job.
+  // Otherwise we'll retry in 30 seconds.
   if (state.commit_result == NETWORK_CONNECTION_UNAVAILABLE ||
       state.last_download_updates_result == NETWORK_CONNECTION_UNAVAILABLE) {
-    return short_initial_backoff_;
+    return default_initial_backoff_;
   }
 
   if (SyncerErrorIsError(state.last_get_key_result))
     return default_initial_backoff_;
 
   // Note: If we received a MIGRATION_DONE on download updates, then commit
   // should not have taken place.  Moreover, if we receive a MIGRATION_DONE
   // on commit, it means that download updates succeeded.  Therefore, we only
   // need to check if either code is equal to SERVER_RETURN_MIGRATION_DONE,
   // and not if there were any more serious errors requiring the long retry.
@@ skipping 15 matching lines @@
   // TODO(sync): We shouldn't need to handle this in BackoffDelayProvider.
   // There should be a way to deal with protocol errors before we get to this
   // point.
   if (state.commit_result == SERVER_RETURN_CONFLICT)
     return short_initial_backoff_;
 
   return default_initial_backoff_;
 }
 
 }  // namespace syncer