[ObjC ARC] Converts components/translate/ios/browser:browser to ARC.

components/translate/ios/browser/translate_controller.mm

Index: components/translate/ios/browser/translate_controller.mm
diff --git a/components/translate/ios/browser/translate_controller.mm b/components/translate/ios/browser/translate_controller.mm
index 6035ba5e9e7339d3ae7cf38825195e0a144780fc..ea181c6fce4f79f058522c598fc81a12f0fb826d 100644
--- a/components/translate/ios/browser/translate_controller.mm
+++ b/components/translate/ios/browser/translate_controller.mm
@@ -12,6 +12,10 @@
 #import "components/translate/ios/browser/js_translate_manager.h"
 #include "ios/web/public/web_state/web_state.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace translate {
 
 namespace {
@@ -24,7 +28,7 @@ TranslateController::TranslateController(web::WebState* web_state,
                                          JsTranslateManager* manager)
     : web::WebStateObserver(web_state),
       observer_(nullptr),
-      js_manager_([manager retain]),
+      js_manager_(manager),
       weak_method_factory_(this) {
   DCHECK(js_manager_);
   DCHECK(web::WebStateObserver::web_state());