PVer4: Verify checksum for downloaded updates

components/safe_browsing_db/v4_database.cc

Index: components/safe_browsing_db/v4_database.cc
diff --git a/components/safe_browsing_db/v4_database.cc b/components/safe_browsing_db/v4_database.cc
index 59bea71a173cbbe51756d6d8333a402e2c1ef61e..f341d121aa8e22256601e093e10af2cf72bed525 100644
--- a/components/safe_browsing_db/v4_database.cc
+++ b/components/safe_browsing_db/v4_database.cc
@@ -139,6 +139,8 @@ void V4Database::UpdatedStoreReady(UpdateListIdentifier identifier,
   DCHECK(pending_store_updates_);
   if (new_store) {
     (*store_map_)[identifier] = std::move(new_store);
+  } else {
+    DVLOG(1) << "Store update discarded: " << *(*store_map_)[identifier];
   }
 
   pending_store_updates_--;