Expose way to enable/disable translate.

ios/web_view/internal/translate/cwv_translation_controller.mm

Index: ios/web_view/internal/translate/cwv_translation_controller.mm
diff --git a/ios/web_view/internal/translate/cwv_translation_controller.mm b/ios/web_view/internal/translate/cwv_translation_controller.mm
index 17ed9e99831dac924f91ad294a7bd0d3526293d2..26c2df5564829cae7dce1438f99e6f1241a67607 100644
--- a/ios/web_view/internal/translate/cwv_translation_controller.mm
+++ b/ios/web_view/internal/translate/cwv_translation_controller.mm
@@ -11,6 +11,7 @@
 #include "base/strings/sys_string_conversions.h"
 #include "components/translate/core/browser/translate_download_manager.h"
 #include "components/translate/core/browser/translate_manager.h"
+#include "components/translate/core/browser/translate_pref_names.h"
 #import "ios/web_view/internal/cwv_web_view_configuration_internal.h"
 #include "ios/web_view/internal/pref_names.h"
 #import "ios/web_view/internal/translate/cwv_translation_language_internal.h"
@@ -79,6 +80,22 @@ const NSInteger CWVTranslationErrorScriptLoadError =
   translatePrefs.ResetToDefaults();
 }
 
++ (BOOL)isTranslateEnabled {
+  CWVWebViewConfiguration* configuration =
+      [CWVWebViewConfiguration defaultConfiguration];
+  PrefService* prefService = configuration.browserState->GetPrefs();
+  translate::TranslatePrefs translatePrefs(prefService, prefs::kAcceptLanguages,
+                                           nullptr);
+  return translatePrefs.IsEnabled();
+}
+
++ (void)setTranslateEnabled:(BOOL)enabled {
+  CWVWebViewConfiguration* configuration =
+      [CWVWebViewConfiguration defaultConfiguration];
+  PrefService* prefService = configuration.browserState->GetPrefs();
+  prefService->SetBoolean(prefs::kEnableTranslate, enabled);
+}
+
 #pragma mark - Internal Methods
 
 - (void)setWebState:(web::WebState*)webState {