PVer4: Test checksum on startup outside the hotpath of DB load

components/safe_browsing_db/v4_local_database_manager.cc

Index: components/safe_browsing_db/v4_local_database_manager.cc
diff --git a/components/safe_browsing_db/v4_local_database_manager.cc b/components/safe_browsing_db/v4_local_database_manager.cc
index 28320252fec77167878326768d915c7ef53f9ae8..9e5a92dc22b1cbe6c6f415b8e7080b00a40f1290 100644
--- a/components/safe_browsing_db/v4_local_database_manager.cc
+++ b/components/safe_browsing_db/v4_local_database_manager.cc
@@ -272,7 +272,7 @@ void V4LocalDatabaseManager::StopOnIOThread(bool shutdown) {
 // End: SafeBrowsingDatabaseManager implementation
 //
 
-void V4LocalDatabaseManager::DatabaseReady(
+void V4LocalDatabaseManager::DatabaseReadyForChecks(
     std::unique_ptr<V4Database> v4_database) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
@@ -281,9 +281,17 @@ void V4LocalDatabaseManager::DatabaseReady(
   if (enabled_) {
     v4_database_ = std::move(v4_database);
 
-    // The database is in place. Start fetching updates now.
-    v4_update_protocol_manager_->ScheduleNextUpdate(
-        v4_database_->GetStoreStateMap());
+    // The consistency of the stores read from the disk needs to verified. Post
+    // that task on the task runner. It calls |db_ready_for_updates_callback|
+    // callback with the stores to reset, if any, and then we can schedule the
+    // database updates.
+    DatabaseReadyForUpdatesCallback db_ready_for_updates_callback =
+        base::Bind(&V4LocalDatabaseManager::DatabaseReadyForUpdates,
+                   base::Unretained(this));
+    task_runner_->PostTask(FROM_HERE,
+                           base::Bind(&V4Database::VerifyChecksum,
+                                      base::Unretained(v4_database_.get()),
+                                      db_ready_for_updates_callback));
 
     ProcessQueuedChecks();
   } else {
@@ -292,6 +300,17 @@ void V4LocalDatabaseManager::DatabaseReady(
   }
 }
 
+void V4LocalDatabaseManager::DatabaseReadyForUpdates(
+    const std::unordered_set<ListIdentifier>& stores_to_reset) {
+  if (enabled_) {
+    v4_database_->ResetStores(stores_to_reset);
+
+    // The database is ready to process updates. Start fetching them now.
+    v4_update_protocol_manager_->ScheduleNextUpdate(
+        v4_database_->GetStoreStateMap());
+  }
+}
+
 void V4LocalDatabaseManager::DatabaseUpdated() {
   if (enabled_) {
     v4_update_protocol_manager_->ScheduleNextUpdate(
@@ -456,7 +475,7 @@ void V4LocalDatabaseManager::SetupDatabase() {
   // operation. Instead, do that on the task_runner and when the new database
   // has been created, swap it out on the IO thread.
   NewDatabaseReadyCallback db_ready_callback = base::Bind(
-      &V4LocalDatabaseManager::DatabaseReady, base::Unretained(this));
+      &V4LocalDatabaseManager::DatabaseReadyForChecks, base::Unretained(this));
   V4Database::Create(task_runner_, base_path_, list_infos_, db_ready_callback);
 }