Restore KeyedServiceFactory diagnostics for context use-after-destroy.

chrome/browser/push_messaging/push_messaging_service_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 "chrome/browser/push_messaging/push_messaging_service_impl.h"
 
 #include <vector>
 
 #include "base/barrier_closure.h"
 #include "base/base64url.h"
@@ skipping 145 matching lines @@
     : profile_(profile),
       push_subscription_count_(0),
       pending_push_subscription_count_(0),
       notification_manager_(profile),
       push_messaging_service_observer_(PushMessagingServiceObserver::Create()),
       weak_factory_(this) {
   DCHECK(profile);
   HostContentSettingsMapFactory::GetForProfile(profile_)->AddObserver(this);
 }
 
-PushMessagingServiceImpl::~PushMessagingServiceImpl() {
-  HostContentSettingsMapFactory::GetForProfile(profile_)->RemoveObserver(this);
-}
+PushMessagingServiceImpl::~PushMessagingServiceImpl() = default;
 
 void PushMessagingServiceImpl::IncreasePushSubscriptionCount(int add,
                                                              bool is_pending) {
   DCHECK(add > 0);
   if (push_subscription_count_ + pending_push_subscription_count_ == 0) {
     GetGCMDriver()->AddAppHandler(kPushMessagingAppIdentifierPrefix, this);
   }
   if (is_pending) {
     pending_push_subscription_count_ += add;
   } else {
@@ skipping 740 matching lines @@
 
 void PushMessagingServiceImpl::SetContentSettingChangedCallbackForTesting(
     const base::Closure& callback) {
   content_setting_changed_callback_for_testing_ = callback;
 }
 
 // KeyedService methods -------------------------------------------------------
 
 void PushMessagingServiceImpl::Shutdown() {
   GetGCMDriver()->RemoveAppHandler(kPushMessagingAppIdentifierPrefix);
+  HostContentSettingsMapFactory::GetForProfile(profile_)->RemoveObserver(this);
 }
 
 // BackgroundTrigger methods ---------------------------------------------------
 base::string16 PushMessagingServiceImpl::GetName() {
   return l10n_util::GetStringUTF16(IDS_NOTIFICATIONS_BACKGROUND_SERVICE_NAME);
 }
 
 gfx::ImageSkia* PushMessagingServiceImpl::GetIcon() {
   return nullptr;
 }
@@ skipping 50 matching lines @@
 }
 
 instance_id::InstanceIDDriver* PushMessagingServiceImpl::GetInstanceIDDriver()
     const {
   instance_id::InstanceIDProfileService* instance_id_profile_service =
       instance_id::InstanceIDProfileServiceFactory::GetForProfile(profile_);
   CHECK(instance_id_profile_service);
   CHECK(instance_id_profile_service->driver());
   return instance_id_profile_service->driver();
 }