Parse messages.json in ExtensionUnpacker (like we do for manifest)....

chrome/common/extensions/extension_unittest.cc

 // Copyright (c) 2009 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 "base/file_path.h"
 #include "base/file_util.h"
 #include "base/string_util.h"
 #include "base/path_service.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/extensions/extension.h"
@@ skipping 31 matching lines @@
       .AppendASCII("1.0.0.0")
       .AppendASCII(Extension::kManifestFilename);
 
   JSONFileValueSerializer serializer(extensions_path);
   scoped_ptr<DictionaryValue> valid_value(
       static_cast<DictionaryValue*>(serializer.Deserialize(&error)));
   EXPECT_EQ("", error);
   ASSERT_TRUE(valid_value.get());
   ASSERT_TRUE(extension.InitFromValue(*valid_value, true, &error));
   ASSERT_EQ("", error);
+  EXPECT_EQ("en_US", extension.default_locale());
 
   scoped_ptr<DictionaryValue> input_value;
 
   // Test missing and invalid versions
   input_value.reset(static_cast<DictionaryValue*>(valid_value->DeepCopy()));
   input_value->Remove(keys::kVersion, NULL);
   EXPECT_FALSE(extension.InitFromValue(*input_value, true, &error));
   EXPECT_EQ(errors::kInvalidVersion, error);
 
   input_value->SetInteger(keys::kVersion, 42);
@@ skipping 169 matching lines @@
   input_value->Set(keys::kPageActions, action_list);
   input_value->Set(keys::kBrowserAction, action);
   EXPECT_FALSE(extension.InitFromValue(*input_value, true, &error));
   EXPECT_STREQ(error.c_str(), errors::kOneUISurfaceOnly);
 
   // Test invalid options page url.
   input_value.reset(static_cast<DictionaryValue*>(valid_value->DeepCopy()));
   input_value->Set(keys::kOptionsPage, Value::CreateNullValue());
   EXPECT_FALSE(extension.InitFromValue(*input_value, true, &error));
   EXPECT_TRUE(MatchPattern(error, errors::kInvalidOptionsPage));
+
+  // Test invalid/empty default locale.
+  input_value.reset(static_cast<DictionaryValue*>(valid_value->DeepCopy()));
+  input_value->Set(keys::kDefaultLocale, Value::CreateIntegerValue(5));
+  EXPECT_FALSE(extension.InitFromValue(*input_value, true, &error));
+  EXPECT_TRUE(MatchPattern(error, errors::kInvalidDefaultLocale));
+
+  input_value->Set(keys::kDefaultLocale, Value::CreateStringValue(""));
+  EXPECT_FALSE(extension.InitFromValue(*input_value, true, &error));
+  EXPECT_TRUE(MatchPattern(error, errors::kInvalidDefaultLocale));
 }
 
 TEST(ExtensionTest, InitFromValueValid) {
 #if defined(OS_WIN)
   FilePath path(FILE_PATH_LITERAL("C:\\foo"));
 #elif defined(OS_POSIX)
   FilePath path(FILE_PATH_LITERAL("/foo"));
 #endif
   Extension extension(path);
   std::string error;
@@ skipping 404 matching lines @@
     scoped_ptr<Extension> new_extension(
         LoadManifest("allow_silent_upgrade",
                      std::string(kTests[i].base_name) + "_new.json"));
 
     EXPECT_EQ(kTests[i].expect_success,
               Extension::IsPrivilegeIncrease(old_extension.get(),
                                              new_extension.get()))
         << kTests[i].base_name;
   }
 }