Notify GCMAppHandlers when the store is reset, so they clear cached IDs

components/proximity_auth/cryptauth/cryptauth_gcm_manager_impl.cc

 // Copyright 2015 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/proximity_auth/cryptauth/cryptauth_gcm_manager_impl.h"
 
 #include "base/bind.h"
 #include "base/strings/string_util.h"
 #include "components/gcm_driver/gcm_driver.h"
 #include "components/prefs/pref_service.h"
@@ skipping 65 matching lines @@
   observers_.AddObserver(observer);
 }
 
 void CryptAuthGCMManagerImpl::RemoveObserver(Observer* observer) {
   observers_.RemoveObserver(observer);
 }
 
 void CryptAuthGCMManagerImpl::ShutdownHandler() {
 }
 
+void CryptAuthGCMManagerImpl::OnStoreReset() {
+  pref_service_->ClearPref(prefs::kCryptAuthGCMRegistrationId);
+}
+
 void CryptAuthGCMManagerImpl::OnMessage(const std::string& app_id,
                                         const gcm::IncomingMessage& message) {
   std::vector<std::string> fields;
   for (const auto& kv : message.data) {
     fields.push_back(std::string(kv.first) + ": " + std::string(kv.second));
   }
 
   PA_LOG(INFO) << "GCM message received:\n"
                << "  sender_id: " << message.sender_id << "\n"
                << "  collapse_key: " << message.collapse_key << "\n"
@@ skipping 45 matching lines @@
   }
 
   PA_LOG(INFO) << "GCM registration success, registration_id="
                << registration_id;
   pref_service_->SetString(prefs::kCryptAuthGCMRegistrationId, registration_id);
   for (auto& observer : observers_)
     observer.OnGCMRegistrationResult(true);
 }
 
 }  // namespace proximity_auth