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

components/safe_browsing_db/v4_store_unittest.cc

Index: components/safe_browsing_db/v4_store_unittest.cc
diff --git a/components/safe_browsing_db/v4_store_unittest.cc b/components/safe_browsing_db/v4_store_unittest.cc
index 90c6525fa88ca316d0051a6fabf0e73147e51e6f..3b747e1ea826afeac98182ca7dc1df295734d780 100644
--- a/components/safe_browsing_db/v4_store_unittest.cc
+++ b/components/safe_browsing_db/v4_store_unittest.cc
@@ -800,4 +800,20 @@ TEST_F(V4StoreTest, TestMergeUpdatesFailsChecksum) {
                 .MergeUpdate(prefix_map_old, HashPrefixMap(), nullptr, "aawc"));
 }
 
+TEST_F(V4StoreTest, TestChecksumErrorOnStartup) {
+  HashPrefixMap prefix_map_additions;
+  EXPECT_EQ(APPLY_UPDATE_SUCCESS,
+            V4Store::AddUnlumpedHashes(4, "2222", &prefix_map_additions));
+  V4Store store(task_runner_, store_path_);
+  EXPECT_EQ(APPLY_UPDATE_SUCCESS,
+            store.MergeUpdate(HashPrefixMap(), prefix_map_additions, nullptr,
+                              "aawc"));
+  EXPECT_FALSE(store.hash_prefix_map_.empty());
+
+  task_runner_->RunPendingTasks();
+  base::RunLoop().RunUntilIdle();
+
+  EXPECT_TRUE(store.hash_prefix_map_.empty());
+}
+
 }  // namespace safe_browsing