Expose method to reset translate settings.

ios/web_view/internal/cwv_web_view_configuration.mm

Index: ios/web_view/internal/cwv_web_view_configuration.mm
diff --git a/ios/web_view/internal/cwv_web_view_configuration.mm b/ios/web_view/internal/cwv_web_view_configuration.mm
index d123fbf31269fb56a676e6837bc5750f6fc7caf5..52f18d79e63e6e59410c9b5ab7b8c2a741924f6c 100644
--- a/ios/web_view/internal/cwv_web_view_configuration.mm
+++ b/ios/web_view/internal/cwv_web_view_configuration.mm
@@ -7,9 +7,10 @@
 
 #include "base/memory/ptr_util.h"
 #include "base/threading/thread_restrictions.h"
-#include "components/translate/core/browser/translate_download_manager.h"
+#include "components/translate/core/browser/translate_prefs.h"
 #include "ios/web_view/internal/app/application_context.h"
 #import "ios/web_view/internal/cwv_user_content_controller_internal.h"
+#include "ios/web_view/internal/pref_names.h"
 #include "ios/web_view/internal/web_view_browser_state.h"
 #include "ios/web_view/internal/web_view_global_state_util.h"
 
@@ -62,10 +63,20 @@
   return self;
 }
 
+#pragma mark - Public Methods
+
+- (void)resetTranslationPreferences {
+  translate::TranslatePrefs translatePrefs(_browserState->GetPrefs(),
+                                           prefs::kAcceptLanguages, nullptr);
+  translatePrefs.ResetToDefaults();
+}
+
 - (BOOL)isPersistent {
   return !_browserState->IsOffTheRecord();
 }
 
+#pragma mark - Private Methods
+
 - (ios_web_view::WebViewBrowserState*)browserState {
   return _browserState.get();
 }