Make push messaging not create InvalidationService for login and guest

chrome/browser/invalidation/invalidation_service_factory.h

 // Copyright (c) 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_INVALIDATION_INVALIDATION_SERVICE_FACTORY_H_
 #define CHROME_BROWSER_INVALIDATION_INVALIDATION_SERVICE_FACTORY_H_
 
 #include "base/basictypes.h"
 #include "base/memory/singleton.h"
 #include "components/keyed_service/content/browser_context_keyed_service_factory.h"
@@ skipping 14 matching lines @@
 class InvalidationService;
 class P2PInvalidationService;
 
 // A BrowserContextKeyedServiceFactory to construct InvalidationServices.  The
 // implementation of the InvalidationService may be completely different on
 // different platforms; this class should help to hide this complexity.  It also
 // exposes some factory methods that are useful for setting up tests that rely
 // on invalidations.
 class InvalidationServiceFactory : public BrowserContextKeyedServiceFactory {
  public:
+  // Returns the InvalidationService for the given |profile|, lazily creating
+  // one first if required. If |profile| does not support invalidation
+  // (Chrome OS login profile, Chrome OS guest), returns NULL instead.
   static InvalidationService* GetForProfile(Profile* profile);
 
   static InvalidationServiceFactory* GetInstance();
 
   // Switches service creation to go through |testing_factory| for all browser
   // contexts.
   void RegisterTestingFactory(TestingFactoryFunction testing_factory);
 
  private:
   friend struct DefaultSingletonTraits<InvalidationServiceFactory>;
 
   InvalidationServiceFactory();
   virtual ~InvalidationServiceFactory();
 
   // BrowserContextKeyedServiceFactory:
   virtual KeyedService* BuildServiceInstanceFor(
       content::BrowserContext* context) const OVERRIDE;
   virtual void RegisterProfilePrefs(
       user_prefs::PrefRegistrySyncable* registry) OVERRIDE;
 
   TestingFactoryFunction testing_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(InvalidationServiceFactory);
 };
 
 }  // namespace invalidation
 
 #endif  // CHROME_BROWSER_INVALIDATION_INVALIDATION_SERVICE_FACTORY_H_