Fix a crash during shutdown where SafeBrowsingProtocolManager could end up getting back NULL for Pro

chrome/browser/safe_browsing/protocol_manager.h

 // Copyright (c) 2006-2008 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_SAFE_BROWSING_PROTOCOL_MANAGER_H_
 #define CHROME_BROWSER_SAFE_BROWSING_PROTOCOL_MANAGER_H_
 
 // A class that implements Chrome's interface with the SafeBrowsing protocol.
 // The SafeBrowsingProtocolManager handles formatting and making requests of,
 // and handling responses from, Google's SafeBrowsing servers. This class uses
@@ skipping 30 matching lines @@
 }
 #endif
 
 class SafeBrowsingProtocolManager : public URLFetcher::Delegate {
   // Testing friends:
   FRIEND_TEST(SafeBrowsingProtocolManagerTest, TestBackOffTimes);
   FRIEND_TEST(SafeBrowsingProtocolManagerTest, TestChunkStrings);
   FRIEND_TEST(SafeBrowsingProtocolManagerTest, TestGetHashBackOffTimes);
 
  public:
+  // Constructs a SafeBrowsingProtocolManager for |sb_service| that issues
+  // network requests using |request_context_getter|.
   SafeBrowsingProtocolManager(SafeBrowsingService* sb_service,
                               const std::string& client_name,
                               const std::string& client_key,
-                              const std::string& wrapped_key);
+                              const std::string& wrapped_key,
+                              URLRequestContextGetter* request_context_getter);
   ~SafeBrowsingProtocolManager();
 
   // Set up the update schedule and internal state for making periodic requests
   // of the SafeBrowsing service.
   void Initialize();
 
   // URLFetcher::Delegate interface.
   virtual void OnURLFetchComplete(const URLFetcher* source,
                                   const GURL& url,
                                   const URLRequestStatus& status,
@@ skipping 164 matching lines @@
 
   // Track the size of each update (in bytes).
   int update_size_;
 
   // Track outstanding malware report fetchers for clean up.
   std::set<const URLFetcher*> malware_reports_;
 
   // The safe browsing client name sent in each request.
   std::string client_name_;
 
+  // The context we use to issue network requests.
+  scoped_refptr<URLRequestContextGetter> request_context_getter_;
+
   DISALLOW_COPY_AND_ASSIGN(SafeBrowsingProtocolManager);
 };
 
 #endif  // CHROME_BROWSER_SAFE_BROWSING_PROTOCOL_MANAGER_H_