[GCM] Update backoff policy to be more conservative.

google_apis/gcm/gcm_client_impl.cc

 // Copyright 2013 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 "google_apis/gcm/gcm_client_impl.h"
 
 #include "base/bind.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/sequenced_task_runner.h"
 #include "base/time/default_clock.h"
 #include "google_apis/gcm/base/mcs_message.h"
 #include "google_apis/gcm/base/mcs_util.h"
 #include "google_apis/gcm/engine/checkin_request.h"
 #include "google_apis/gcm/engine/connection_factory_impl.h"
 #include "google_apis/gcm/engine/gcm_store_impl.h"
 #include "google_apis/gcm/engine/mcs_client.h"
 #include "google_apis/gcm/engine/registration_request.h"
 #include "google_apis/gcm/protocol/mcs.pb.h"
 #include "net/http/http_network_session.h"
 #include "net/url_request/url_request_context.h"
 #include "url/gurl.h"
 
 namespace gcm {
 
 namespace {
 
-// Backoff policy. Shared across reconnection logic and checkin/registration
+// Backoff policy. Shared across reconnection logic and checkin/(un)registration
 // retries.
+// Note: In order to ensure a minimum of 20 seconds between server errors (for
+// server reasons), we have a 30s +- 10s (33%) jitter initial backoff.
 // TODO(zea): consider sharing/synchronizing the scheduling of backoff retries
 // themselves.
 const net::BackoffEntry::Policy kDefaultBackoffPolicy = {
   // Number of initial errors (in sequence) to ignore before applying
   // exponential back-off rules.
   0,
 
   // Initial delay for exponential back-off in ms.
-  15000,  // 15 seconds.
+  30 * 1000,  // 30 seconds.
 
   // Factor by which the waiting time will be multiplied.
   2,
 
   // Fuzzing percentage. ex: 10% will spread requests randomly
   // between 90%-100% of the calculated time.
-  0.5,  // 50%.
+  0.33,  // 33%.
 
   // Maximum amount of time we are willing to delay our request in ms.
-  1000 * 60 * 5, // 5 minutes.
+  10 * 60 * 1000, // 10 minutes.
 
   // Time to keep an entry from being discarded even when it
   // has no significant state, -1 to never discard.
   -1,
 
   // Don't use initial delay unless the last request was an error.
   false,
 };
 
 // Indicates a message type of the received message.
@@ skipping 389 matching lines @@
   if (iter != incoming_message.data.end())
     message_id = iter->second;
   delegate->OnMessageSendError(app_id, message_id, SERVER_ERROR);
 }
 
 void GCMClientImpl::SetMCSClientForTesting(scoped_ptr<MCSClient> mcs_client) {
   mcs_client_ = mcs_client.Pass();
 }
 
 }  // namespace gcm