[Live Caption] Only show Live Caption promo to users who have English as

one of their languages.

Since Live Caption currently only works for English, we should not
advertise the feature to users who we do not expect to want English
captions. We can make a guess as to which users would want English
caption by checking whether English is one of the user's fluent
languages, found in chrome://settings/languages.

Bug: 1169760, 1055150
Change-Id: Id16e99de1edb777b8d5b2d793f0dcbefc925935d
AX-Relnotes: Live Caption only promoted to English-language users.
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2643443Reviewed-by: Tommy Steimel <steimel@chromium.org>
Commit-Queue: Abigail Klein <abigailbklein@google.com>
Cr-Commit-Position: refs/heads/master@{#846273}

chrome/browser/ui/views/global_media_controls/media_toolbar_button_view.cc

@@ -5,8 +5,10 @@
 #include "chrome/browser/ui/views/global_media_controls/media_toolbar_button_view.h"
 
 #include "base/feature_list.h"
+#include "base/strings/pattern.h"
 #include "build/build_config.h"
 #include "chrome/app/vector_icons/vector_icons.h"
+#include "chrome/browser/language/language_model_manager_factory.h"
 #include "chrome/browser/themes/theme_properties.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/global_media_controls/media_notification_service_factory.h"
@@ -17,6 +19,8 @@
 #include "chrome/browser/ui/views/user_education/feature_promo_controller_views.h"
 #include "chrome/grit/generated_resources.h"
 #include "components/feature_engagement/public/feature_constants.h"
+#include "components/language/core/browser/language_model.h"
+#include "components/language/core/browser/language_model_manager.h"
 #include "components/vector_icons/vector_icons.h"
 #include "media/base/media_switches.h"
 #include "ui/base/l10n/l10n_util.h"
@@ -86,9 +90,21 @@ void MediaToolbarButtonView::Hide() {
 void MediaToolbarButtonView::Enable() {
   SetEnabled(true);
 
-  if (base::FeatureList::IsEnabled(media::kLiveCaption)) {
-    feature_promo_controller_->MaybeShowPromo(
-        feature_engagement::kIPHLiveCaptionFeature);
+  // Live Caption only works for English-language speech for now, so we only
+  // show the promo to users whose fluent languages include english. Fluent
+  // languages are set in chrome://settings/languages.
+  // TODO(crbug.com/1161569): Remove this when Live Caption supports additional
+  // languages.
+  language::LanguageModel* language_model =
+      LanguageModelManagerFactory::GetForBrowserContext(browser_->profile())
+          ->GetPrimaryModel();
+  for (const auto& lang : language_model->GetLanguages()) {
+    if (base::MatchPattern(lang.lang_code, "en*") &&
+        base::FeatureList::IsEnabled(media::kLiveCaption)) {
+      feature_promo_controller_->MaybeShowPromo(
+          feature_engagement::kIPHLiveCaptionFeature);
+      break;
+    }
   }
 
   for (auto& observer : observers_)