Cleanup AdjustStringForLocaleDirection() to modify input parameter in place.

As described in the bug, the current behavior is confusing and bug-prone.

BUG=47194
TEST=Check that there are no visible regressions in RTL and LTR language UIs on Linux & Windows.

Review URL: http://codereview.chromium.org/5154009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@67237 0039d316-1c4b-4281-b951-d872f2087c98

30 files changed, 77 insertions, 144 deletions

diff --git a/app/win_util.cc b/app/win_util.cc
index be267af..b3a0571 100644
--- a/app/win_util.cc
+++ b/app/win_util.cc
@@ -533,15 +533,13 @@ int MessageBox(HWND hwnd,
   if (base::i18n::IsRTL())
     actual_flags |= MB_RIGHT | MB_RTLREADING;
 
-  std::wstring localized_text;
-  const wchar_t* text_ptr = text.c_str();
-  if (base::i18n::AdjustStringForLocaleDirection(text, &localized_text))
-    text_ptr = localized_text.c_str();
-
-  std::wstring localized_caption;
-  const wchar_t* caption_ptr = caption.c_str();
-  if (base::i18n::AdjustStringForLocaleDirection(caption, &localized_caption))
-    caption_ptr = localized_caption.c_str();
+  std::wstring localized_text = text;
+  base::i18n::AdjustStringForLocaleDirection(&localized_text);
+  const wchar_t* text_ptr = localized_text.c_str();
+
+  std::wstring localized_caption = caption;
+  base::i18n::AdjustStringForLocaleDirection(&localized_caption);
+  const wchar_t* caption_ptr = localized_caption.c_str();
 
   return ::MessageBox(hwnd, text_ptr, caption_ptr, actual_flags);
 }
diff --git a/base/i18n/rtl.cc b/base/i18n/rtl.cc
index 0881fb7..6a5d293 100644
--- a/base/i18n/rtl.cc
+++ b/base/i18n/rtl.cc
@@ -163,30 +163,27 @@ TextDirection GetFirstStrongCharacterDirection(const std::wstring& text) {
 }
 #endif
 
-bool AdjustStringForLocaleDirection(const string16& text,
-                                    string16* localized_text) {
-  if (!IsRTL() || text.empty())
+bool AdjustStringForLocaleDirection(string16* text) {
+  if (!IsRTL() || text->empty())
     return false;
 
   // Marking the string as LTR if the locale is RTL and the string does not
   // contain strong RTL characters. Otherwise, mark the string as RTL.
-  *localized_text = text;
-  bool has_rtl_chars = StringContainsStrongRTLChars(text);
+  bool has_rtl_chars = StringContainsStrongRTLChars(*text);
   if (!has_rtl_chars)
-    WrapStringWithLTRFormatting(localized_text);
+    WrapStringWithLTRFormatting(text);
   else
-    WrapStringWithRTLFormatting(localized_text);
+    WrapStringWithRTLFormatting(text);
 
   return true;
 }
 
 #if defined(WCHAR_T_IS_UTF32)
-bool AdjustStringForLocaleDirection(const std::wstring& text,
-                                    std::wstring* localized_text) {
-  string16 out;
-  if (AdjustStringForLocaleDirection(WideToUTF16(text), &out)) {
+bool AdjustStringForLocaleDirection(std::wstring* text) {
+  string16 temp = WideToUTF16(*text);
+  if (AdjustStringForLocaleDirection(&temp)) {
     // We should only touch the output on success.
-    *localized_text = UTF16ToWide(out);
+    *text = UTF16ToWide(temp);
     return true;
   }
   return false;
diff --git a/base/i18n/rtl.h b/base/i18n/rtl.h
index ed0882f..82ac576 100644
--- a/base/i18n/rtl.h
+++ b/base/i18n/rtl.h
@@ -71,13 +71,12 @@ TextDirection GetFirstStrongCharacterDirection(const string16& text);
 TextDirection GetFirstStrongCharacterDirection(const std::wstring& text);
 #endif
 
-// Given the string in |text|, this function creates a copy of the string with
+// Given the string in |text|, this function modifies the string in place with
 // the appropriate Unicode formatting marks that mark the string direction
-// (either left-to-right or right-to-left). The new string is returned in
-// |localized_text|. The function checks both the current locale and the
-// contents of the string in order to determine the direction of the returned
-// string. The function returns true if the string in |text| was properly
-// adjusted.
+// (either left-to-right or right-to-left). The function checks both the current
+// locale and the contents of the string in order to determine the direction of
+// the returned string. The function returns true if the string in |text| was
+// properly adjusted.
 //
 // Certain LTR strings are not rendered correctly when the context is RTL. For
 // example, the string "Foo!" will appear as "!Foo" if it is rendered as is in
@@ -85,16 +84,7 @@ TextDirection GetFirstStrongCharacterDirection(const std::wstring& text);
 // string is always treated as a right-to-left string. This is done by
 // inserting certain Unicode formatting marks into the returned string.
 //
-// TODO(brettw) bug 47194: This funciton is confusing. If it does no adjustment
-// becuase the current locale is not RTL, it will do nothing and return false.
-// This means you have to check the return value in many cases which doesn't
-// make sense. This should be cleaned up and probably just take a single
-// argument that's a pointer to a string that it modifies as necessary. In the
-// meantime, the recommended usage is to use the same arg as input & output,
-// which will work without extra checks:
-//   AdjustStringForLocaleDirection(text, &text);
-//
-// TODO(idana) bug# 1206120: this function adjusts the string in question only
+// TODO(idana) bug 6806: this function adjusts the string in question only
 // if the current locale is right-to-left. The function does not take care of
 // the opposite case (an RTL string displayed in an LTR context) since
 // adjusting the string involves inserting Unicode formatting characters that
@@ -102,11 +92,9 @@ TextDirection GetFirstStrongCharacterDirection(const std::wstring& text);
 // installed. Since the English version of Windows doesn't have right-to-left
 // language support installed by default, inserting the direction Unicode mark
 // results in Windows displaying squares.
-bool AdjustStringForLocaleDirection(const string16& text,
-                                    string16* localized_text);
+bool AdjustStringForLocaleDirection(string16* text);
 #if defined(WCHAR_T_IS_UTF32)
-bool AdjustStringForLocaleDirection(const std::wstring& text,
-                                    std::wstring* localized_text);
+bool AdjustStringForLocaleDirection(std::wstring* text);
 #endif
 
 // Returns true if the string contains at least one character with strong right
diff --git a/chrome/browser/browser_main_win.cc b/chrome/browser/browser_main_win.cc
index de6f2f1..f4f9a59 100644
--- a/chrome/browser/browser_main_win.cc
+++ b/chrome/browser/browser_main_win.cc
@@ -134,7 +134,7 @@ void PrepareRestartOnCrashEnviroment(const CommandLine &parsed_command_line) {
   dlg_strings.push_back('|');
   string16 adjusted_string(
       l10n_util::GetStringUTF16(IDS_CRASH_RECOVERY_CONTENT));
-  base::i18n::AdjustStringForLocaleDirection(adjusted_string, &adjusted_string);
+  base::i18n::AdjustStringForLocaleDirection(&adjusted_string);
   dlg_strings.append(adjusted_string);
   dlg_strings.push_back('|');
   dlg_strings.append(ASCIIToUTF16(
diff --git a/chrome/browser/chromeos/dom_ui/imageburner_ui.cc b/chrome/browser/chromeos/dom_ui/imageburner_ui.cc
index 709a061..b827c93 100644
--- a/chrome/browser/chromeos/dom_ui/imageburner_ui.cc
+++ b/chrome/browser/chromeos/dom_ui/imageburner_ui.cc
@@ -312,20 +312,13 @@ std::wstring ImageBurnHandler::GetBurnProgressText(int64 total_burnt,
   std::wstring burnt_size =
       UTF16ToWideHack(FormatBytes(total_burnt, amount_units, true));
 
-  std::wstring burnt_size_localized;
-  if (base::i18n::AdjustStringForLocaleDirection(burnt_size,
-                                                 &burnt_size_localized)) {
-    burnt_size.assign(burnt_size_localized);
-  }
+  base::i18n::AdjustStringForLocaleDirection(&burnt_size);
 
   if (image_size) {
     amount_units = GetByteDisplayUnits(image_size);
     std::wstring total_text =
         UTF16ToWideHack(FormatBytes(image_size, amount_units, true));
-    std::wstring total_text_localized;
-    if (base::i18n::AdjustStringForLocaleDirection(total_text,
-                                                   &total_text_localized))
-    total_text.assign(total_text_localized);
+    base::i18n::AdjustStringForLocaleDirection(&total_text);
 
     return l10n_util::GetStringF(IDS_IMAGEBURN_BURN_PROGRESS,
                                  burnt_size,
diff --git a/chrome/browser/chromeos/dom_ui/system_settings_provider.cc b/chrome/browser/chromeos/dom_ui/system_settings_provider.cc
index 2c6fe6a..77350f4 100644
--- a/chrome/browser/chromeos/dom_ui/system_settings_provider.cc
+++ b/chrome/browser/chromeos/dom_ui/system_settings_provider.cc
@@ -272,9 +272,8 @@ string16 SystemSettingsProvider::GetTimezoneName(
   string16 result(l10n_util::GetStringFUTF16(
       IDS_OPTIONS_SETTINGS_TIMEZONE_DISPLAY_TEMPLATE, ASCIIToUTF16(offset_str),
       string16(name.getBuffer(), name.length()), GetExemplarCity(timezone)));
-  string16 rtl_safe_result = result;
-  base::i18n::AdjustStringForLocaleDirection(result, &rtl_safe_result);
-  return rtl_safe_result;
+  base::i18n::AdjustStringForLocaleDirection(&result);
+  return result;
 }
 
 string16 SystemSettingsProvider::GetTimezoneID(
diff --git a/chrome/browser/dom_ui/dom_ui.cc b/chrome/browser/dom_ui/dom_ui.cc
index e6481b6..06c7d2d 100644
--- a/chrome/browser/dom_ui/dom_ui.cc
+++ b/chrome/browser/dom_ui/dom_ui.cc
@@ -179,9 +179,7 @@ void DOMMessageHandler::SetURLAndTitle(DictionaryValue* dictionary,
     if (using_url_as_the_title) {
       base::i18n::WrapStringWithLTRFormatting(&title_to_set);
     } else {
-      bool success =
-          base::i18n::AdjustStringForLocaleDirection(title, &title_to_set);
-      DCHECK(success ? (title != title_to_set) : (title == title_to_set));
+      base::i18n::AdjustStringForLocaleDirection(&title_to_set);
     }
   }
   dictionary->SetString("title", title_to_set);
diff --git a/chrome/browser/download/download_util.cc b/chrome/browser/download/download_util.cc
index c7a261f..2c856be 100644
--- a/chrome/browser/download/download_util.cc
+++ b/chrome/browser/download/download_util.cc
@@ -544,21 +544,15 @@ std::wstring GetProgressStatusText(DownloadItem* download) {
 
   // Adjust both strings for the locale direction since we don't yet know which
   // string we'll end up using for constructing the final progress string.
-  std::wstring amount_localized;
-  if (base::i18n::AdjustStringForLocaleDirection(amount, &amount_localized)) {
-    amount.assign(amount_localized);
-    received_size.assign(amount_localized);
-  }
+  base::i18n::AdjustStringForLocaleDirection(&amount);
 
   if (total) {
     amount_units = GetByteDisplayUnits(total);
     std::wstring total_text =
         UTF16ToWideHack(FormatBytes(total, amount_units, true));
-    std::wstring total_text_localized;
-    if (base::i18n::AdjustStringForLocaleDirection(total_text,
-                                                   &total_text_localized))
-      total_text.assign(total_text_localized);
+    base::i18n::AdjustStringForLocaleDirection(&total_text);
 
+    base::i18n::AdjustStringForLocaleDirection(&received_size);
     amount = l10n_util::GetStringF(IDS_DOWNLOAD_TAB_PROGRESS_SIZE,
                                    received_size,
                                    total_text);
@@ -569,10 +563,7 @@ std::wstring GetProgressStatusText(DownloadItem* download) {
   amount_units = GetByteDisplayUnits(current_speed);
   std::wstring speed_text = UTF16ToWideHack(FormatSpeed(current_speed,
                                                         amount_units, true));
-  std::wstring speed_text_localized;
-  if (base::i18n::AdjustStringForLocaleDirection(speed_text,
-                                                 &speed_text_localized))
-    speed_text.assign(speed_text_localized);
+  base::i18n::AdjustStringForLocaleDirection(&speed_text);
 
   base::TimeDelta remaining;
   string16 time_remaining;
@@ -582,6 +573,7 @@ std::wstring GetProgressStatusText(DownloadItem* download) {
     time_remaining = TimeFormat::TimeRemaining(remaining);
 
   if (time_remaining.empty()) {
+    base::i18n::AdjustStringForLocaleDirection(&amount);
     return l10n_util::GetStringF(IDS_DOWNLOAD_TAB_PROGRESS_STATUS_TIME_UNKNOWN,
                                  speed_text, amount);
   }
diff --git a/chrome/browser/encoding_menu_controller.cc b/chrome/browser/encoding_menu_controller.cc
index d53536d..7d3a89e 100644
--- a/chrome/browser/encoding_menu_controller.cc
+++ b/chrome/browser/encoding_menu_controller.cc
@@ -131,10 +131,7 @@ void EncodingMenuController::GetEncodingMenuItems(Profile* profile,
   for (it = encodings->begin(); it != encodings->end(); ++it) {
     if (it->encoding_id) {
       std::wstring encoding = it->encoding_display_name;
-      std::wstring bidi_safe_encoding;
-      if (base::i18n::AdjustStringForLocaleDirection(encoding,
-                                                     &bidi_safe_encoding))
-        encoding.swap(bidi_safe_encoding);
+      base::i18n::AdjustStringForLocaleDirection(&encoding);
       menuItems->push_back(EncodingMenuItem(it->encoding_id,
                                             WideToUTF16(encoding)));
     } else {
diff --git a/chrome/browser/language_combobox_model.cc b/chrome/browser/language_combobox_model.cc
index 55b98d4..c2787b8 100644
--- a/chrome/browser/language_combobox_model.cc
+++ b/chrome/browser/language_combobox_model.cc
@@ -90,21 +90,11 @@ std::wstring LanguageList::GetLanguageNameAt(int index) const {
   // We must add directionality formatting to both the native name and the
   // locale name in order to avoid text rendering problems such as misplaced
   // parentheses or languages appearing in the wrong order.
-  std::wstring locale_name_localized;
-  std::wstring locale_name;
-  if (base::i18n::AdjustStringForLocaleDirection(locale_names_[index],
-                                                 &locale_name_localized))
-    locale_name.assign(locale_name_localized);
-  else
-    locale_name.assign(locale_names_[index]);
+  std::wstring locale_name = locale_names_[index];
+  base::i18n::AdjustStringForLocaleDirection(&locale_name);
 
-  std::wstring native_name_localized;
-  std::wstring native_name;
-  if (base::i18n::AdjustStringForLocaleDirection(it->second.native_name,
-                                                 &native_name_localized))
-    native_name.assign(native_name_localized);
-  else
-    native_name.assign(it->second.native_name);
+  std::wstring native_name = it->second.native_name;
+  base::i18n::AdjustStringForLocaleDirection(&native_name);
 
   // We used to have a localizable template here, but none of translators
   // changed the format. We also want to switch the order of locale_name
diff --git a/chrome/browser/location_bar_util.cc b/chrome/browser/location_bar_util.cc
index 3542070d..a398ada 100644
--- a/chrome/browser/location_bar_util.cc
+++ b/chrome/browser/location_bar_util.cc
@@ -35,7 +35,7 @@ std::wstring CalculateMinString(const std::wstring& description) {
   } else {
     min_string = description.substr(0, chop_index);
   }
-  base::i18n::AdjustStringForLocaleDirection(min_string, &min_string);
+  base::i18n::AdjustStringForLocaleDirection(&min_string);
   return min_string;
 }
 
diff --git a/chrome/browser/possible_url_model.cc b/chrome/browser/possible_url_model.cc
index f419762..d84c54f 100644
--- a/chrome/browser/possible_url_model.cc
+++ b/chrome/browser/possible_url_model.cc
@@ -132,13 +132,11 @@ std::wstring PossibleURLModel::GetText(int row, int col_id) {
   }
 
   if (col_id == IDS_ASI_PAGE_COLUMN) {
-    const std::wstring& title = GetTitle(row);
+    std::wstring title = GetTitle(row);
     // TODO(xji): Consider adding a special case if the title text is a URL,
     // since those should always have LTR directionality. Please refer to
     // http://crbug.com/6726 for more information.
-    std::wstring localized_title;
-    if (base::i18n::AdjustStringForLocaleDirection(title, &localized_title))
-      return localized_title;
+    base::i18n::AdjustStringForLocaleDirection(&title);
     return title;
   }
 
diff --git a/chrome/browser/search_engines/template_url.cc b/chrome/browser/search_engines/template_url.cc
index 48f5d7d..c1ebf517 100644
--- a/chrome/browser/search_engines/template_url.cc
+++ b/chrome/browser/search_engines/template_url.cc
@@ -578,11 +578,9 @@ TemplateURL::~TemplateURL() {
 }
 
 std::wstring TemplateURL::AdjustedShortNameForLocaleDirection() const {
-  std::wstring bidi_safe_short_name;
-  if (base::i18n::AdjustStringForLocaleDirection(short_name_,
-                                                 &bidi_safe_short_name))
-    return bidi_safe_short_name;
-  return short_name_;
+  std::wstring bidi_safe_short_name = short_name_;
+  base::i18n::AdjustStringForLocaleDirection(&bidi_safe_short_name);
+  return bidi_safe_short_name;
 }
 
 void TemplateURL::SetSuggestionsURL(const std::string& suggestions_url,
diff --git a/chrome/browser/search_engines/template_url_table_model.cc b/chrome/browser/search_engines/template_url_table_model.cc
index 4570b25..f335ba3 100644
--- a/chrome/browser/search_engines/template_url_table_model.cc
+++ b/chrome/browser/search_engines/template_url_table_model.cc
@@ -187,8 +187,7 @@ std::wstring TemplateURLTableModel::GetText(int row, int col_id) {
       // TODO(xji): Consider adding a special case if the short name is a URL,
       // since those should always be displayed LTR. Please refer to
       // http://crbug.com/6726 for more information.
-      base::i18n::AdjustStringForLocaleDirection(url_short_name,
-                                                 &url_short_name);
+      base::i18n::AdjustStringForLocaleDirection(&url_short_name);
       return (template_url_model_->GetDefaultSearchProvider() == &url) ?
           l10n_util::GetStringF(IDS_SEARCH_ENGINES_EDITOR_DEFAULT_ENGINE,
                                 url_short_name) : url_short_name;
diff --git a/chrome/browser/task_manager/task_manager.cc b/chrome/browser/task_manager/task_manager.cc
index c6500fa..5673741 100644
--- a/chrome/browser/task_manager/task_manager.cc
+++ b/chrome/browser/task_manager/task_manager.cc
@@ -500,7 +500,7 @@ string16 TaskManagerModel::GetMemCellText(int64 number) const {
   string16 str = base::FormatNumber(number / 1024);
 
   // Adjust number string if necessary.
-  base::i18n::AdjustStringForLocaleDirection(str, &str);
+  base::i18n::AdjustStringForLocaleDirection(&str);
   return l10n_util::GetStringFUTF16(IDS_TASK_MANAGER_MEM_CELL_TEXT, str);
 #else
   // System expectation is to show "100 KB", "200 MB", etc.
diff --git a/chrome/browser/task_manager/task_manager_resource_providers.cc b/chrome/browser/task_manager/task_manager_resource_providers.cc
index 73476c9..2b339fa 100644
--- a/chrome/browser/task_manager/task_manager_resource_providers.cc
+++ b/chrome/browser/task_manager/task_manager_resource_providers.cc
@@ -149,7 +149,7 @@ std::wstring TaskManagerTabContentsResource::GetTitle() const {
     // as LTR format, the concatenated result will be "!Yahoo! Mail: The best
     // web-based Email :BAT", in which the capital letters "BAT" stands for
     // the Hebrew word for "tab".
-    base::i18n::AdjustStringForLocaleDirection(tab_title, &tab_title);
+    base::i18n::AdjustStringForLocaleDirection(&tab_title);
   }
 
   return l10n_util::GetStringF(IDS_TASK_MANAGER_TAB_PREFIX, tab_title);
@@ -357,8 +357,7 @@ TaskManagerBackgroundContentsResource::TaskManagerBackgroundContentsResource(
   }
   // Ensure that the string has the appropriate direction markers (see comment
   // in TaskManagerTabContentsResource::GetTitle()).
-  base::i18n::AdjustStringForLocaleDirection(application_name_,
-                                             &application_name_);
+  base::i18n::AdjustStringForLocaleDirection(&application_name_);
 }
 
 TaskManagerBackgroundContentsResource::~TaskManagerBackgroundContentsResource(
diff --git a/chrome/browser/ui/views/bookmark_bar_view.cc b/chrome/browser/ui/views/bookmark_bar_view.cc
index 439df1d..6226524 100644
--- a/chrome/browser/ui/views/bookmark_bar_view.cc
+++ b/chrome/browser/ui/views/bookmark_bar_view.cc
@@ -143,9 +143,8 @@ static std::wstring CreateToolTipForURLAndTitle(const gfx::Point& screen_loc,
 
   // First the title.
   if (!title.empty()) {
-    std::wstring localized_title;
-    if (!base::i18n::AdjustStringForLocaleDirection(title, &localized_title))
-      localized_title = title;
+    std::wstring localized_title = title;
+    base::i18n::AdjustStringForLocaleDirection(&localized_title);
     result.append(UTF16ToWideHack(gfx::ElideText(WideToUTF16Hack(
         localized_title), tt_font, max_width, false)));
   }
diff --git a/chrome/browser/ui/views/hung_renderer_view.cc b/chrome/browser/ui/views/hung_renderer_view.cc
index 3482380..b50debf 100644
--- a/chrome/browser/ui/views/hung_renderer_view.cc
+++ b/chrome/browser/ui/views/hung_renderer_view.cc
@@ -97,7 +97,7 @@ std::wstring HungPagesTableModel::GetText(int row, int column_id) {
   // TODO(xji): Consider adding a special case if the title text is a URL,
   // since those should always have LTR directionality. Please refer to
   // http://crbug.com/6726 for more information.
-  base::i18n::AdjustStringForLocaleDirection(title, &title);
+  base::i18n::AdjustStringForLocaleDirection(&title);
   return title;
 }
 
diff --git a/chrome/browser/ui/views/options/passwords_page_view.cc b/chrome/browser/ui/views/options/passwords_page_view.cc
index 6d22d5e..e33b0b6 100644
--- a/chrome/browser/ui/views/options/passwords_page_view.cc
+++ b/chrome/browser/ui/views/options/passwords_page_view.cc
@@ -82,7 +82,7 @@ std::wstring PasswordsTableModel::GetText(int row,
     }
     case IDS_PASSWORDS_PAGE_VIEW_USERNAME_COLUMN: {  // Username.
       std::wstring username = GetPasswordFormAt(row)->username_value;
-      base::i18n::AdjustStringForLocaleDirection(username, &username);
+      base::i18n::AdjustStringForLocaleDirection(&username);
       return username;
     }
     default:
diff --git a/chrome/common/child_process_info.cc b/chrome/common/child_process_info.cc
index 1af0cdb..8774578 100644
--- a/chrome/common/child_process_info.cc
+++ b/chrome/common/child_process_info.cc
@@ -82,7 +82,7 @@ string16 ChildProcessInfo::GetLocalizedTitle() const {
   // to avoid the wrong concatenation result similar to "!Yahoo! Mail: the
   // best web-based Email: NIGULP", in which "NIGULP" stands for the Hebrew
   // or Arabic word for "plugin".
-  base::i18n::AdjustStringForLocaleDirection(title, &title);
+  base::i18n::AdjustStringForLocaleDirection(&title);
 
   switch (type_) {
     case ChildProcessInfo::UTILITY_PROCESS:
diff --git a/chrome/common/extensions/extension.cc b/chrome/common/extensions/extension.cc
index 4d33822..ba316b8 100644
--- a/chrome/common/extensions/extension.cc
+++ b/chrome/common/extensions/extension.cc
@@ -1234,7 +1234,7 @@ bool Extension::InitFromValue(const DictionaryValue& source, bool require_key,
     *error = errors::kInvalidName;
     return false;
   }
-  base::i18n::AdjustStringForLocaleDirection(localized_name, &localized_name);
+  base::i18n::AdjustStringForLocaleDirection(&localized_name);
   name_ = UTF16ToUTF8(localized_name);
 
   // Initialize description (if present).
diff --git a/chrome/common/extensions/extension_unittest.cc b/chrome/common/extensions/extension_unittest.cc
index 3f86bbd..013fce7 100644
--- a/chrome/common/extensions/extension_unittest.cc
+++ b/chrome/common/extensions/extension_unittest.cc
@@ -383,7 +383,7 @@ TEST(ExtensionTest, InitFromValueValidNameInRTL) {
   EXPECT_TRUE(extension.InitFromValue(input_value, false, &error));
   EXPECT_EQ("", error);
   std::wstring localized_name(name);
-  base::i18n::AdjustStringForLocaleDirection(localized_name, &localized_name);
+  base::i18n::AdjustStringForLocaleDirection(&localized_name);
   EXPECT_EQ(localized_name, UTF8ToWide(extension.name()));
 
   // Strong RTL characters in name.
@@ -392,7 +392,7 @@ TEST(ExtensionTest, InitFromValueValidNameInRTL) {
   EXPECT_TRUE(extension.InitFromValue(input_value, false, &error));
   EXPECT_EQ("", error);
   localized_name = name;
-  base::i18n::AdjustStringForLocaleDirection(localized_name, &localized_name);
+  base::i18n::AdjustStringForLocaleDirection(&localized_name);
   EXPECT_EQ(localized_name, UTF8ToWide(extension.name()));
 
   // Reset locale.
diff --git a/gfx/canvas_skia_win.cc b/gfx/canvas_skia_win.cc
index 1a65da0..dd8c96a 100644
--- a/gfx/canvas_skia_win.cc
+++ b/gfx/canvas_skia_win.cc
@@ -19,17 +19,18 @@ void DoDrawText(HDC hdc,
                 const std::wstring& text,
                 RECT* text_bounds,
                 int flags) {
-  std::wstring localized_text;
-  const wchar_t* string_ptr = text.c_str();
-  int string_size = static_cast<int>(text.length());
   // Only adjust string directionality if both of the following are true:
   // 1. The current locale is RTL.
   // 2. The string itself has RTL directionality.
+  const wchar_t* string_ptr = text.c_str();
+  int string_size = static_cast<int>(text.length());
+
+  std::wstring localized_text;
   if (flags & DT_RTLREADING) {
-    if (base::i18n::AdjustStringForLocaleDirection(text, &localized_text)) {
-      string_ptr = localized_text.c_str();
-      string_size = static_cast<int>(localized_text.length());
-    }
+    localized_text = text;
+    base::i18n::AdjustStringForLocaleDirection(&localized_text);
+    string_ptr = localized_text.c_str();
+    string_size = static_cast<int>(localized_text.length());
   }
 
   DrawText(hdc, string_ptr, string_size, text_bounds, flags);
diff --git a/views/controls/button/native_button.cc b/views/controls/button/native_button.cc
index 89dae9c..e1693d3 100644
--- a/views/controls/button/native_button.cc
+++ b/views/controls/button/native_button.cc
@@ -74,9 +74,7 @@ void NativeButton::SetLabel(const std::wstring& label) {
   // In order to overcome this problem, we mark the localized Hebrew strings as
   // RTL strings explicitly (using the appropriate Unicode formatting) so that
   // Windows displays the text correctly regardless of the HWND hierarchy.
-  std::wstring localized_label;
-  if (base::i18n::AdjustStringForLocaleDirection(label_, &localized_label))
-    label_ = localized_label;
+  base::i18n::AdjustStringForLocaleDirection(&label_);
 
   if (native_wrapper_)
     native_wrapper_->UpdateLabel();
diff --git a/views/controls/combobox/native_combobox_win.cc b/views/controls/combobox/native_combobox_win.cc
index 720e51f..2134a75e 100644
--- a/views/controls/combobox/native_combobox_win.cc
+++ b/views/controls/combobox/native_combobox_win.cc
@@ -47,14 +47,12 @@ void NativeComboboxWin::UpdateFromModel() {
   int max_width = 0;
   int num_items = combobox_->model()->GetItemCount();
   for (int i = 0; i < num_items; ++i) {
-    const std::wstring& text = UTF16ToWide(combobox_->model()->GetItemAt(i));
+    std::wstring text = UTF16ToWide(combobox_->model()->GetItemAt(i));
 
     // Inserting the Unicode formatting characters if necessary so that the
     // text is displayed correctly in right-to-left UIs.
-    std::wstring localized_text;
+    base::i18n::AdjustStringForLocaleDirection(&text);
     const wchar_t* text_ptr = text.c_str();
-    if (base::i18n::AdjustStringForLocaleDirection(text, &localized_text))
-      text_ptr = localized_text.c_str();
 
     SendMessage(native_view(), CB_ADDSTRING, 0,
                 reinterpret_cast<LPARAM>(text_ptr));
diff --git a/views/controls/textfield/native_textfield_win.cc b/views/controls/textfield/native_textfield_win.cc
index 2109cb9..3f4b0eb 100644
--- a/views/controls/textfield/native_textfield_win.cc
+++ b/views/controls/textfield/native_textfield_win.cc
@@ -155,13 +155,11 @@ void NativeTextfieldWin::UpdateText() {
   std::wstring text = textfield_->text();
   // Adjusting the string direction before setting the text in order to make
   // sure both RTL and LTR strings are displayed properly.
-  std::wstring text_to_set;
-  if (!base::i18n::AdjustStringForLocaleDirection(text, &text_to_set))
-    text_to_set = text;
+  base::i18n::AdjustStringForLocaleDirection(&text);
   if (textfield_->style() & Textfield::STYLE_LOWERCASE)
-    text_to_set = l10n_util::ToLower(text_to_set);
-  SetWindowText(text_to_set.c_str());
-  UpdateAccessibleValue(text_to_set);
+    text = l10n_util::ToLower(text);
+  SetWindowText(text.c_str());
+  UpdateAccessibleValue(text);
 }
 
 void NativeTextfieldWin::AppendText(const string16& text) {
diff --git a/views/controls/tree/tree_view.cc b/views/controls/tree/tree_view.cc
index 6b02a62..bfdd454 100644
--- a/views/controls/tree/tree_view.cc
+++ b/views/controls/tree/tree_view.cc
@@ -370,9 +370,7 @@ LRESULT TreeView::OnNotify(int w_param, LPNMHDR l_param) {
         DCHECK(info->item.cchTextMax);
 
         // Adjust the string direction if such adjustment is required.
-        std::wstring localized_text;
-        if (base::i18n::AdjustStringForLocaleDirection(text, &localized_text))
-          text.swap(localized_text);
+        base::i18n::AdjustStringForLocaleDirection(&text);
 
         wcsncpy_s(info->item.pszText, info->item.cchTextMax, text.c_str(),
                   _TRUNCATE);
diff --git a/views/widget/tooltip_manager_win.cc b/views/widget/tooltip_manager_win.cc
index c7ad4ff..8e51e64 100644
--- a/views/widget/tooltip_manager_win.cc
+++ b/views/widget/tooltip_manager_win.cc
@@ -173,8 +173,7 @@ LRESULT TooltipManagerWin::OnNotify(int w_param,
             TrimTooltipToFit(&clipped_text_, &tooltip_width_, &line_count_,
                              screen_loc.x(), screen_loc.y());
             // Adjust the clipped tooltip text for locale direction.
-            base::i18n::AdjustStringForLocaleDirection(clipped_text_,
-                                                       &clipped_text_);
+            base::i18n::AdjustStringForLocaleDirection(&clipped_text_);
             tooltip_info->lpszText = const_cast<WCHAR*>(clipped_text_.c_str());
           } else {
             tooltip_text_.clear();
diff --git a/views/window/window_gtk.cc b/views/window/window_gtk.cc
index d59d7a5..4f8a251 100644
--- a/views/window/window_gtk.cc
+++ b/views/window/window_gtk.cc
@@ -207,9 +207,7 @@ void WindowGtk::UpdateWindowTitle() {
   // Update the native frame's text. We do this regardless of whether or not
   // the native frame is being used, since this also updates the taskbar, etc.
   std::wstring window_title = window_delegate_->GetWindowTitle();
-  std::wstring localized_text;
-  if (base::i18n::AdjustStringForLocaleDirection(window_title, &localized_text))
-    window_title.assign(localized_text);
+  base::i18n::AdjustStringForLocaleDirection(&window_title);
 
   gtk_window_set_title(GetNativeWindow(), WideToUTF8(window_title).c_str());
 }
diff --git a/views/window/window_win.cc b/views/window/window_win.cc
index 03bf75f..e940fdd 100644
--- a/views/window/window_win.cc
+++ b/views/window/window_win.cc
@@ -417,9 +417,7 @@ void WindowWin::UpdateWindowTitle() {
     window_title = window_delegate_->GetAccessibleWindowTitle();
   else
     window_title = window_delegate_->GetWindowTitle();
-  std::wstring localized_text;
-  if (base::i18n::AdjustStringForLocaleDirection(window_title, &localized_text))
-    window_title.assign(localized_text);
+  base::i18n::AdjustStringForLocaleDirection(&window_title);
   SetWindowText(GetNativeView(), window_title.c_str());
 
   // Also update the accessibility name.