[Android] Add flag for detailed language settings feature

This CL adds the DetailedLanguageSettings feature to chrome://flags
on Android.

Bug: 1068667
Change-Id: I6b4bc7aeb0fe00741ea553e89459713834f79e9d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2405942
Reviewed-by: Megan Jablonski <[email protected]>
Commit-Queue: Trevor  Perrier <[email protected]>
Cr-Commit-Position: refs/heads/master@{#806309}
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index c46d211..6018ce87 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -6397,6 +6397,13 @@
      FEATURE_VALUE_TYPE(messages::kMessagesForAndroidPasswords)},
 #endif
 
+#if defined(OS_ANDROID)
+    {"android-detailed-language-settings",
+     flag_descriptions::kAndroidDetailedLanguageSettingsName,
+     flag_descriptions::kAndroidDetailedLanguageSettingsDescription, kOsAndroid,
+     FEATURE_VALUE_TYPE(language::kDetailedLanguageSettings)},
+#endif
+
     // NOTE: Adding a new flag requires adding a corresponding entry to enum
     // "LoginCustomFlags" in tools/metrics/histograms/enums.xml. See "Flag
     // Histograms" in tools/metrics/histograms/README.md (run the