Enable the side-effect free whitelist and use it for local browsing based

chrome/browser/safe_browsing/database_manager.h

 // Copyright (c) 2012 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.
 //
 // The Safe Browsing service is responsible for downloading anti-phishing and
 // anti-malware tables and checking urls against them.
 
 #ifndef CHROME_BROWSER_SAFE_BROWSING_DATABASE_MANAGER_H_
 #define CHROME_BROWSER_SAFE_BROWSING_DATABASE_MANAGER_H_
 
@@ skipping 129 matching lines @@
   // Result will be passed to callback in |client|.
   virtual bool CheckDownloadHash(const std::string& full_hash, Client* client);
 
   // Check which prefixes in |extension_ids| are in the safebrowsing blacklist.
   // Returns true if not, false if further checks need to be made in which case
   // the result will be passed to |client|.
   virtual bool CheckExtensionIDs(const std::set<std::string>& extension_ids,
                                  Client* client);
 
   // Check if the given url is on the side-effect free whitelist.
-  // Can be called on any thread.
+  // Can be called on any thread. Returns false if the check cannot be performed
+  // (e.g. because we are disabled or because of an invalid scheme in the URL).
+  // Otherwise, returns true if the URL is on the whitelist based on matching
+  // the hash prefix only (so there may be false positives).
   virtual bool CheckSideEffectFreeWhitelistUrl(const GURL& url);
 
   // Check if the |url| matches any of the full-length hashes from the
   // client-side phishing detection whitelist.  Returns true if there was a
   // match and false otherwise.  To make sure we are conservative we will return
   // true if an error occurs. This method is expected to be called on the IO
   // thread.
   virtual bool MatchCsdWhitelistUrl(const GURL& url);
 
   // Check if the |url| matches any of the full-length hashes from the
@@ skipping 234 matching lines @@
 
   std::deque<QueuedCheck> queued_checks_;
 
   // Timeout to use for safe browsing checks.
   base::TimeDelta check_timeout_;
 
   DISALLOW_COPY_AND_ASSIGN(SafeBrowsingDatabaseManager);
 };
 
 #endif  // CHROME_BROWSER_SAFE_BROWSING_DATABASE_MANAGER_H_