Safebrowsing: grab lookup_lock_ when clearing browse_gethash_cache_ during update.

chrome/browser/safe_browsing/safe_browsing_database.cc

 // 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.
 
 #include "chrome/browser/safe_browsing/safe_browsing_database.h"
 
 #include <algorithm>
 #include <iterator>
 
 #include "base/bind.h"
@@ skipping 995 matching lines @@
     HandleCorruptDatabase();
     return false;
   }
 
   if (ip_blacklist_store_ && !ip_blacklist_store_->BeginUpdate()) {
     RecordFailure(FAILURE_IP_BLACKLIST_UPDATE_BEGIN);
     HandleCorruptDatabase();
     return false;
   }
 
-  // Cached fullhash results must be cleared on every database update (whether
-  // successful or not.)
-  browse_gethash_cache_.clear();
+  {
+    base::AutoLock locked(lookup_lock_);
+    // Cached fullhash results must be cleared on every database update (whether
+    // successful or not.)
+    browse_gethash_cache_.clear();
+  }
 
   UpdateChunkRangesForLists(browse_store_.get(),
                             safe_browsing_util::kMalwareList,
                             safe_browsing_util::kPhishingList,
                             lists);
 
   // NOTE(shess): |download_store_| used to contain kBinHashList, which has been
   // deprecated.  Code to delete the list from the store shows ~15k hits/day as
   // of Feb 2014, so it has been removed.  Everything _should_ be resilient to
   // extra data of that sort.
@@ skipping 535 matching lines @@
 bool SafeBrowsingDatabaseNew::IsMalwareIPMatchKillSwitchOn() {
   SBFullHash malware_kill_switch = SBFullHashForString(kMalwareIPKillSwitchUrl);
   std::vector<SBFullHash> full_hashes;
   full_hashes.push_back(malware_kill_switch);
   return ContainsWhitelistedHashes(csd_whitelist_, full_hashes);
 }
 
 bool SafeBrowsingDatabaseNew::IsCsdWhitelistKillSwitchOn() {
   return csd_whitelist_.second;
 }