Make V4GetHashProtocolManager::RegisterFactory safe.

components/safe_browsing_db/v4_get_hash_protocol_manager.h

 // Copyright 2016 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 COMPONENTS_SAFE_BROWSING_DB_V4_GET_HASH_PROTOCOL_MANAGER_H_
 #define COMPONENTS_SAFE_BROWSING_DB_V4_GET_HASH_PROTOCOL_MANAGER_H_
 
 // A class that implements Chrome's interface with the SafeBrowsing V4 protocol.
 //
 // The V4GetHashProtocolManager handles formatting and making requests of, and
@@ skipping 34 matching lines @@
   //     were no matches, and that the resource is safe.
   //   - The negative cache duration of the result.
   typedef base::Callback<void(const std::vector<SBFullHashResult>&,
                               const base::TimeDelta&)>
       FullHashCallback;
 
   ~V4GetHashProtocolManager() override;
 
   // Makes the passed |factory| the factory used to instantiate
   // a V4GetHashProtocolManager. Useful for tests.
-  static void RegisterFactory(V4GetHashProtocolManagerFactory* factory) {
-    factory_ = factory;
-  }
+  static void RegisterFactory(
+      std::unique_ptr<V4GetHashProtocolManagerFactory> factory);
 
   // Create an instance of the safe browsing v4 protocol manager.
   static V4GetHashProtocolManager* Create(
       net::URLRequestContextGetter* request_context_getter,
       const V4ProtocolConfig& config);
 
   // net::URLFetcherDelegate interface.
   void OnURLFetchComplete(const net::URLFetcher* source) override;
 
   // Retrieve the full hash for a set of prefixes, and invoke the callback
@@ skipping 110 matching lines @@
       net::URLRequestContextGetter* request_context_getter,
       const V4ProtocolConfig& config) = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(V4GetHashProtocolManagerFactory);
 };
 
 }  // namespace safe_browsing
 
 #endif  // COMPONENTS_SAFE_BROWSING_DB_V4_GET_HASH_PROTOCOL_MANAGER_H_