[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
diff --git a/chrome/browser/flag-metadata.json b/chrome/browser/flag-metadata.json
index 97dd0a5c..a5eba11a 100644
--- a/chrome/browser/flag-metadata.json
+++ b/chrome/browser/flag-metadata.json
@@ -104,6 +104,11 @@
     "expiry_milestone": 91
   },
   {
+    "name": "android-detailed-language-settings",
+    "owners": [ "perrier", "[email protected]" ],
+    "expiry_milestone": 89
+  },
+  {
     "name": "android-files-in-files-app",
     "owners": [ "fukino" ],
     "expiry_milestone": 76
diff --git a/chrome/browser/flag_descriptions.cc b/chrome/browser/flag_descriptions.cc
index 00350ed..df84181 100644
--- a/chrome/browser/flag_descriptions.cc
+++ b/chrome/browser/flag_descriptions.cc
@@ -2584,6 +2584,11 @@
 const char kAndroidDefaultBrowserPromoDescription[] =
     "Shows a promo dialog to set Chrome as the default browser";
 
+const char kAndroidDetailedLanguageSettingsName[] =
+    "Detailed Language Settings";
+const char kAndroidDetailedLanguageSettingsDescription[] =
+    "Enable the new detailed language settings page";
+
 const char kAndroidManagedByMenuItemName[] = "Managed by menu item";
 const char kAndroidManagedByMenuItemDescription[] =
     "whether policies have been applied to this browser at the profile or "
diff --git a/chrome/browser/flag_descriptions.h b/chrome/browser/flag_descriptions.h
index b0e9a509..0bcb2c6 100644
--- a/chrome/browser/flag_descriptions.h
+++ b/chrome/browser/flag_descriptions.h
@@ -1490,6 +1490,9 @@
 extern const char kAndroidDefaultBrowserPromoName[];
 extern const char kAndroidDefaultBrowserPromoDescription[];
 
+extern const char kAndroidDetailedLanguageSettingsName[];
+extern const char kAndroidDetailedLanguageSettingsDescription[];
+
 extern const char kAndroidManagedByMenuItemName[];
 extern const char kAndroidManagedByMenuItemDescription[];