Add callback to LevelDBWrapperImpl to allow extra operations on commit.

content/browser/dom_storage/local_storage_context_mojo_unittest.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 "content/browser/dom_storage/local_storage_context_mojo.h"
 
 #include "base/run_loop.h"
 #include "components/leveldb/public/cpp/util.h"
 #include "content/public/test/test_browser_thread_bundle.h"
 #include "content/test/mock_leveldb_database.h"
@@ skipping 54 matching lines @@
   auto key = StdStringToUint8Vector("key");
   auto value = StdStringToUint8Vector("value");
 
   mojom::LevelDBWrapperPtr wrapper;
   context()->OpenLocalStorage(url::Origin(GURL("http://foobar.com")),
                               MakeRequest(&wrapper));
   wrapper->Put(key, value, "source", base::Bind(&NoOpSuccess));
   wrapper.reset();
 
   base::RunLoop().RunUntilIdle();
+
   ASSERT_EQ(2u, mock_data().size());
   EXPECT_EQ(value, mock_data().rbegin()->second);
 }
 
 TEST_F(LocalStorageContextMojoTest, OriginsAreIndependent) {
   url::Origin origin1(GURL("http://foobar.com:123"));
   url::Origin origin2(GURL("http://foobar.com:1234"));
   auto key1 = StdStringToUint8Vector("4key");
   auto key2 = StdStringToUint8Vector("key");
   auto value = StdStringToUint8Vector("value");
@@ skipping 42 matching lines @@
   base::RunLoop run_loop;
   bool success = false;
   std::vector<uint8_t> result;
   wrapper->Get(
       StdStringToUint8Vector("key"),
       base::Bind(&GetCallback, run_loop.QuitClosure(), &success, &result));
   run_loop.Run();
   EXPECT_FALSE(success);
 }
 
+TEST_F(LocalStorageContextMojoTest, VersionOnlyWrittenOnCommit) {
+  mojom::LevelDBWrapperPtr wrapper;
+  context()->OpenLocalStorage(url::Origin(GURL("http://foobar.com")),
+                              MakeRequest(&wrapper));
+
+  base::RunLoop run_loop;
+  bool success = false;
+  std::vector<uint8_t> result;
+  wrapper->Get(
+      StdStringToUint8Vector("key"),
+      base::Bind(&GetCallback, run_loop.QuitClosure(), &success, &result));
+  run_loop.Run();
+  EXPECT_FALSE(success);
+  wrapper.reset();
+
+  base::RunLoop().RunUntilIdle();
+  EXPECT_TRUE(mock_data().empty());
+}
+
 }  // namespace content