Fix blank display name for yue-HK in TTS settings page.

This is a temporary fix for the blank display name for yue-HK. The
reason we were returning a blank string is because we were calling
GetDisplayNameForLocale() with the disallow_default parameter. Remove
this parameter so we at least get a return value.

Please see the bug for more context.

readable text label on TTS settings page.

Bug: 1136353
Change-Id: I123c05134782e90c8b297fea6c48287e7fc5dd8c
AX-Relnotes: Fix an issue where the Yue (Hong Kong) voice had no
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2463600
Commit-Queue: Akihiro Ota <akihiroota@chromium.org>
Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Reviewed-by: David Tseng <dtseng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#816296}

chrome/renderer/extensions/accessibility_private_hooks_delegate.cc

@@ -63,21 +63,26 @@ RequestResult AccessibilityPrivateHooksDelegate::HandleGetDisplayNameForLocale(
   const std::string display_locale =
       gin::V8ToString(script_context->isolate(), parsed_arguments[1]);
 
-  std::string locale_result =
-      base::UTF16ToUTF8(l10n_util::GetDisplayNameForLocale(
-          locale, display_locale, true /* is_ui */,
-          true /* disallow_default */));
-
-  RequestResult result(RequestResult::HANDLED);
+  bool found_valid_result = false;
+  std::string locale_result;
+  if (l10n_util::IsValidLocaleSyntax(locale) &&
+      l10n_util::IsValidLocaleSyntax(display_locale)) {
+    locale_result = base::UTF16ToUTF8(l10n_util::GetDisplayNameForLocale(
+        locale, display_locale, true /* is_ui */));
+    // Check for valid locales before getting the display name.
+    // The ICU Locale class returns "und" for undetermined locales, and
+    // returns the locale string directly if it has no translation.
+    // Treat these cases as invalid results.
+    found_valid_result =
+        locale_result != kUndeterminedLocale && locale_result != locale;
+  }
 
-  // Instead of returning "und", which is what the ICU Locale class returns for
-  // undetermined locales, we would simply like to return an empty string to
-  // communicate that we could not determine the display locale. In addition,
-  // ICU returns the |locale| as |result_locale| if it has no translation for a
-  // valid locale. Also return an empty string for that case.
-  if (locale_result == kUndeterminedLocale || locale_result == locale)
+  // We return an empty string to communicate that we could not determine
+  // the display locale.
+  if (!found_valid_result)
     locale_result = std::string();
 
+  RequestResult result(RequestResult::HANDLED);
   result.return_value =
       gin::StringToV8(script_context->isolate(), locale_result);
   return result;

chrome/test/data/extensions/api_test/accessibility_private/display_locale.js

@@ -9,6 +9,9 @@ var allTests = [function testGetDisplayNameForLocale() {
   chrome.test.assertEq(
       'English',
       chrome.accessibilityPrivate.getDisplayNameForLocale('en', 'en'));
+  chrome.test.assertEq(
+      'yue (Hong Kong)',
+      chrome.accessibilityPrivate.getDisplayNameForLocale('yue-HK', 'en'));
   chrome.test.succeed();
 }];
 chrome.test.runTests(allTests);