Push API: Don't wait for network when unsubscribing

components/gcm_driver/gcm_client_impl.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/gcm_driver/gcm_client_impl.h"
 
 #include <stddef.h>
 
 #include <memory>
 #include <utility>
@@ skipping 943 matching lines @@
 
 void GCMClientImpl::OnRegisterCompleted(
     const linked_ptr<RegistrationInfo>& registration_info,
     RegistrationRequest::Status status,
     const std::string& registration_id) {
   DCHECK(delegate_);
 
   Result result;
   PendingRegistrationRequests::const_iterator iter =
       pending_registration_requests_.find(registration_info);
-  if (iter == pending_registration_requests_.end())
+  if (iter == pending_registration_requests_.end()) {
     result = UNKNOWN_ERROR;
-  else if (status == RegistrationRequest::INVALID_SENDER)
+  } else if (status == RegistrationRequest::INVALID_SENDER) {
     result = INVALID_PARAMETER;
-  else if (registration_id.empty())
+  } else if (registration_id.empty()) {
+    // All other errors are currently treated as SERVER_ERROR (including cases
+    // where all retries fail because the device is offline, which might be
+    // expected to result in a NETWORK_ERROR). If this is later changed, update
+    // FakeGCMProfileService's offline simulation to match.

[Peter Beverloo, 2017/02/07 18:11:08]

Here and later, can we shorten and generalize w/ the following?

// NOTE: Update FakeGCMProfileService's offline simulation when splitting
// out additional |result| values.

[johnme, 2017/02/08 14:14:36]

Done (no longer needs to reference FakeGCMProfileService now that the offline
sim is so crude).

     result = SERVER_ERROR;
-  else
+  } else {
     result = SUCCESS;
+  }
 
   if (result == SUCCESS) {
     // Cache it.
     // Note that the existing cached record has to be removed first because
     // otherwise the key value in registrations_ will not be updated. For GCM
     // registrations, the key consists of pair of app_id and sender_ids though
     // only app_id is used in the comparison.
     registrations_.erase(registration_info);
     registrations_[registration_info] = registration_id;
 
@@ skipping 125 matching lines @@
 
   Result result;
   switch (status) {
     case UnregistrationRequest::SUCCESS:
       result = SUCCESS;
       break;
     case UnregistrationRequest::INVALID_PARAMETERS:
       result = INVALID_PARAMETER;
       break;
     default:
-      // All other errors are treated as SERVER_ERROR.
+      // All other errors are currently treated as SERVER_ERROR (including cases
+      // where all retries fail because the device is offline, which might be
+      // expected to result in a NETWORK_ERROR). If this is later changed,
+      // update FakeGCMProfileService's offline simulation to match.
       result = SERVER_ERROR;
       break;
   }
   delegate_->OnUnregisterFinished(registration_info, result);
 
   pending_unregistration_requests_.erase(registration_info);
 }
 
 void GCMClientImpl::OnGCMStoreDestroyed(bool success) {
   DLOG_IF(ERROR, !success) << "GCM store failed to be destroyed!";
@@ skipping 337 matching lines @@
 bool GCMClientImpl::HasStandaloneRegisteredApp() const {
   if (registrations_.empty())
     return false;
   // Note that account mapper is not counted as a standalone app since it is
   // automatically started when other app uses GCM.
   return registrations_.size() > 1 ||
          !ExistsGCMRegistrationInMap(registrations_, kGCMAccountMapperAppId);
 }
 
 }  // namespace gcm