Fix localstorage data migration.

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/files/file_enumerator.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/run_loop.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 46 matching lines @@
                  const std::vector<uint8_t>& value) {
   *success_out = success;
   *value_out = value;
   callback.Run();
 }
 
 void NoOpGet(bool success, const std::vector<uint8_t>& value) {}
 
 std::vector<uint8_t> String16ToUint8Vector(const base::string16& input) {
   const uint8_t* data = reinterpret_cast<const uint8_t*>(input.data());
-  return std::vector<uint8_t>(data, data + input.size() * sizeof(base::char16));
+  std::vector<uint8_t> result;
+  result.reserve(input.size() * sizeof(base::char16) + 1);
+  result.push_back(0);
+  result.insert(result.end(), data, data + input.size() * sizeof(base::char16));

[michaeln, 2017/03/22 23:49:51]

ditto comment about sharing 'format' enum or encode function in some way, maybe
put StorageFormat enum in common/dom_storage_types.h?

also, i'm just noticing these databases aren't portable in the endianness sense,
do we care about that?

[Marijn Kruisselbrink, 2017/03/31 23:06:14]

And I changed it so at least the test here shares the encoding function with
LocalStorageContextMojo by adding it as a static function there.
I think we're okay not being portable endianness wise? But yeah, that's a good
question. I thought somebody said SerializedScriptValue (i.e. indexeddb) isn't
endian safe either, but I'm not sure about that...

+  return result;
 }
 
 class TestLevelDBObserver : public mojom::LevelDBObserver {
  public:
   struct Observation {
     enum { kAdd, kChange, kDelete, kDeleteAll } type;
     std::string key;
     std::string old_value;
     std::string new_value;
     std::string source;
@@ skipping 764 matching lines @@
   base::RunLoop().RunUntilIdle();
 
   // Data should have been preserved now.
   context = base::MakeUnique<LocalStorageContextMojo>(
       connector(), nullptr, base::FilePath(), test_path);
   EXPECT_TRUE(DoTestGet(context.get(), key, &result));
   EXPECT_EQ(value, result);
 }
 
 }  // namespace content