Lands http://codereview.chromium.org/99007 for Yuta.

base/win_util_unittest.cc

Index: base/win_util_unittest.cc
===================================================================
--- base/win_util_unittest.cc	(revision 14677)
+++ base/win_util_unittest.cc	(working copy)
@@ -9,44 +9,9 @@
 #include "base/string_util.h"
 #include "base/win_util.h"
 
-class BaseWinUtilTest: public testing::Test {
- protected:
-  // Retrieve the OS primary language
-  static unsigned GetSystemLanguage() {
-    std::wstring language;
-
-    typedef BOOL (WINAPI *fnGetThreadPreferredUILanguages)(
-        DWORD dwFlags,
-        PULONG pulNumLanguages,
-        PWSTR pwszLanguagesBuffer,
-        PULONG pcchLanguagesBuffer);
-    fnGetThreadPreferredUILanguages pGetThreadPreferredUILanguages = NULL;
-    pGetThreadPreferredUILanguages =
-        reinterpret_cast<fnGetThreadPreferredUILanguages>(
-            GetProcAddress(GetModuleHandle(L"kernel32.dll"),
-                           "GetThreadPreferredUILanguages"));
-    if (pGetThreadPreferredUILanguages) {
-      // Vista, MUI-aware.
-      ULONG number = 0;
-      wchar_t buffer[256] = {0};
-      ULONG buffer_size = sizeof(buffer);
-      EXPECT_TRUE(pGetThreadPreferredUILanguages(MUI_LANGUAGE_ID, &number,
-                                                 buffer, &buffer_size));
-      language = buffer;
-    } else {
-      // XP
-      RegKey language_key(HKEY_LOCAL_MACHINE,
-                          L"SYSTEM\\CurrentControlSet\\Control\\Nls\\Language");
-      language_key.ReadValue(L"InstallLanguage", &language);
-    }
-    wchar_t * unused_endptr;
-    return PRIMARYLANGID(wcstol(language.c_str(), &unused_endptr, 16));
-  }
-};
-
 // The test is somewhat silly, because the Vista bots some have UAC enabled
 // and some have it disabled. At least we check that it does not crash.
-TEST_F(BaseWinUtilTest, TestIsUACEnabled) {
+TEST(BaseWinUtilTest, TestIsUACEnabled) {
   if (win_util::GetWinVersion() >= win_util::WINVERSION_VISTA) {
     win_util::UserAccountControlIsEnabled();
   } else {
@@ -54,13 +19,13 @@
   }
 }
 
-TEST_F(BaseWinUtilTest, TestGetUserSidString) {
+TEST(BaseWinUtilTest, TestGetUserSidString) {
   std::wstring user_sid;
   EXPECT_TRUE(win_util::GetUserSidString(&user_sid));
   EXPECT_TRUE(!user_sid.empty());
 }
 
-TEST_F(BaseWinUtilTest, TestGetNonClientMetrics) {
+TEST(BaseWinUtilTest, TestGetNonClientMetrics) {
   NONCLIENTMETRICS metrics = {0};
   win_util::GetNonClientMetrics(&metrics);
   EXPECT_TRUE(metrics.cbSize > 0);
@@ -68,27 +33,38 @@
   EXPECT_TRUE(metrics.iScrollHeight > 0);
 }
 
-TEST_F(BaseWinUtilTest, FormatMessage) {
-  unsigned language = GetSystemLanguage();
-  ASSERT_TRUE(language);
+namespace {
 
+// Saves the current thread's locale ID when initialized, and restores it when
+// the instance is going out of scope.
+class ThreadLocaleSaver {
+ public:
+  ThreadLocaleSaver() : original_locale_id_(GetThreadLocale()) {}
+  ~ThreadLocaleSaver() { SetThreadLocale(original_locale_id_); }
+
+ private:
+  LCID original_locale_id_;
+
+  DISALLOW_COPY_AND_ASSIGN(ThreadLocaleSaver);
+};
+
+}  // namespace
+
+TEST(BaseWinUtilTest, FormatMessage) {
+  // Because we cannot write tests of every language, we only test the message
+  // of en-US locale. Here, we change the current locale temporarily.
+  ThreadLocaleSaver thread_locale_saver;
+  WORD language_id = MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US);
+  LCID locale_id = MAKELCID(language_id, SORT_DEFAULT);
+  ASSERT_TRUE(SetThreadLocale(locale_id));
+
   const int kAccessDeniedErrorCode = 5;
   SetLastError(kAccessDeniedErrorCode);
   ASSERT_EQ(GetLastError(), kAccessDeniedErrorCode);
   std::wstring value;
+  TrimWhitespace(win_util::FormatLastWin32Error(), TRIM_ALL, &value);
+  EXPECT_EQ(std::wstring(L"Access is denied."), value);
 
-  if (language == LANG_ENGLISH) {
-    // This test would fail on non-English system.
-    TrimWhitespace(win_util::FormatLastWin32Error(), TRIM_ALL, &value);
-    EXPECT_EQ(std::wstring(L"Access is denied."), value);
-  } else if (language == LANG_FRENCH) {
-    // This test would fail on non-French system.
-    TrimWhitespace(win_util::FormatLastWin32Error(), TRIM_ALL, &value);
-    EXPECT_EQ(std::wstring(L"Acc\u00e8s refus\u00e9."), value);
-  } else {
-    EXPECT_TRUE(0) << "Please implement the test for your OS language.";
-  }
-
   // Manually call the OS function
   wchar_t * string_buffer = NULL;
   unsigned string_length =