PVer4: Verify checksum for downloaded updates

components/safe_browsing_db/v4_database.cc

 // 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.
 
 #include <memory>
 
 #include "base/callback.h"
 #include "base/debug/leak_annotations.h"
 #include "base/files/file_util.h"
 #include "base/memory/ptr_util.h"
@@ skipping 121 matching lines @@
     db_updated_callback_.Reset();
   }
 }
 
 void V4Database::UpdatedStoreReady(UpdateListIdentifier identifier,
                                    std::unique_ptr<V4Store> new_store) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DCHECK(pending_store_updates_);
   if (new_store) {
     (*store_map_)[identifier] = std::move(new_store);
+  } else {
+    DVLOG(1) << "Store update discarded: " << *(*store_map_)[identifier];

[Nathan Parker, 2016/08/09 00:10:19]

nit: I suspect this is redundant with the "ApplyUpdate failed" vlog in
v4_store.cc

   }
 
   pending_store_updates_--;
   if (!pending_store_updates_) {
     db_updated_callback_.Run();
     db_updated_callback_.Reset();
   }
 }
 
 bool V4Database::ResetDatabase() {
@@ skipping 25 matching lines @@
     DCHECK(store_pair != store_map_->end());
     const std::unique_ptr<V4Store>& store = store_pair->second;
     HashPrefix hash_prefix = store->GetMatchingHashPrefix(full_hash);
     if (!hash_prefix.empty()) {
       (*matched_hash_prefix_map)[identifier] = hash_prefix;
     }
   }
 }
 
 }  // namespace safe_browsing