Remove misleading BrowserContextKeyedAPI comment.

extensions/browser/browser_context_keyed_api_factory.h

 // 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.
 
 #ifndef EXTENSIONS_BROWSER_BROWSER_CONTEXT_KEYED_API_FACTORY_H_
 #define EXTENSIONS_BROWSER_BROWSER_CONTEXT_KEYED_API_FACTORY_H_
 
 #include "components/keyed_service/content/browser_context_dependency_manager.h"
 #include "components/keyed_service/content/browser_context_keyed_service_factory.h"
 #include "components/keyed_service/core/keyed_service.h"
@@ skipping 25 matching lines @@
 
   // If set to false, don't start the service at BrowserContext creation time.
   // (The default differs from the BrowserContextKeyedBaseFactory default,
   // because historically, BrowserContextKeyedAPIs often do tasks at startup.)
   static const bool kServiceIsCreatedWithBrowserContext = true;
 
   // If set to true, GetForProfile returns NULL for TestingBrowserContexts.
   static const bool kServiceIsNULLWhileTesting = false;
 
   // Users of this factory template must define a GetFactoryInstance()
-  // and manage their own instances (typically using LazyInstance or
-  // Singleton), because those cannot be included in more than one
-  // translation unit (and thus cannot be initialized in a header file).
+  // and manage their own instances (using LazyInstance), because those cannot
+  // be included in more than one translation unit (and thus cannot be
+  // initialized in a header file).
   //
   // In the header file, declare GetFactoryInstance(), e.g.:
   //   class HistoryAPI {
   //   ...
   //    public:
   //     static BrowserContextKeyedAPIFactory<HistoryAPI>* GetFactoryInstance();
   //   };
   //
   // In the cc file, provide the implementation, e.g.:
   //   static base::LazyInstance<BrowserContextKeyedAPIFactory<HistoryAPI> >
@@ skipping 68 matching lines @@
   bool ServiceIsNULLWhileTesting() const override {
     return T::kServiceIsNULLWhileTesting;
   }
 
   DISALLOW_COPY_AND_ASSIGN(BrowserContextKeyedAPIFactory);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_BROWSER_CONTEXT_KEYED_API_FACTORY_H_