Restore KeyedServiceFactory diagnostics for context use-after-destroy.

chrome/browser/extensions/api/signed_in_devices/signed_in_devices_manager.h

 // 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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_API_SIGNED_IN_DEVICES_SIGNED_IN_DEVICES_MANAGER_H__
 #define CHROME_BROWSER_EXTENSIONS_API_SIGNED_IN_DEVICES_SIGNED_IN_DEVICES_MANAGER_H__
 
 #include <memory>
 #include <string>
 #include <vector>
@@ skipping 50 matching lines @@
                                public EventRouter::Observer {
  public:
   // Default constructor used for testing.
   SignedInDevicesManager();
   explicit SignedInDevicesManager(content::BrowserContext* context);
   ~SignedInDevicesManager() override;
 
   // BrowserContextKeyedAPI implementation.
   static BrowserContextKeyedAPIFactory<SignedInDevicesManager>*
       GetFactoryInstance();
+  void Shutdown() override;
 
   // ExtensionRegistryObserver implementation.
   void OnExtensionUnloaded(content::BrowserContext* browser_context,
                            const Extension* extension,
                            UnloadedExtensionInfo::Reason reason) override;
 
   // EventRouter::Observer:
   void OnListenerAdded(const EventListenerInfo& details) override;
   void OnListenerRemoved(const EventListenerInfo& details) override;
 
@@ skipping 16 matching lines @@
       extension_registry_observer_;
 
   FRIEND_TEST_ALL_PREFIXES(SignedInDevicesManager, UpdateListener);
 
   DISALLOW_COPY_AND_ASSIGN(SignedInDevicesManager);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_SIGNED_IN_DEVICES_SIGNED_IN_DEVICES_MANAGER_H__