Replace OnPageTranslate Obsever by a responder of delegate.

components/translate/core/browser/translate_infobar_delegate.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/translate/core/browser/translate_infobar_delegate.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/feature_list.h"
@@ skipping 83 matching lines @@
     return;
   }
 
   // Find any existing translate infobar delegate.
   infobars::InfoBar* old_infobar = NULL;
   TranslateInfoBarDelegate* old_delegate = NULL;
   for (size_t i = 0; i < infobar_manager->infobar_count(); ++i) {
     old_infobar = infobar_manager->infobar_at(i);
     old_delegate = old_infobar->delegate()->AsTranslateInfoBarDelegate();
     if (old_delegate) {
-      if (!replace_existing_infobar || IsCompactUIEnabled())
+      if (!replace_existing_infobar)
         return;
       break;
     }
   }
 
+  // Try to reuse existing translate infobar delegate.
+  if (old_delegate && old_delegate->responder_) {
+    old_delegate->responder_->ActionOnStep(step, error_type);
+    return;
+  }
+
   // Add the new delegate.
   TranslateClient* translate_client = translate_manager->translate_client();
   std::unique_ptr<infobars::InfoBar> infobar(translate_client->CreateInfoBar(
       base::WrapUnique(new TranslateInfoBarDelegate(
           translate_manager, is_off_the_record, step, original_language,
           target_language, error_type, triggered_from_menu))));
   if (old_delegate)
     infobar_manager->ReplaceInfoBar(old_infobar, std::move(infobar));
   else
     infobar_manager->AddInfoBar(std::move(infobar));
 }
 
 // static
 bool TranslateInfoBarDelegate::IsCompactUIEnabled() {
   return base::FeatureList::IsEnabled(kTranslateCompactUI);
 }
 
+void TranslateInfoBarDelegate::SetResponder(Responder* responder) {
+  responder_ = responder;
+}
+
 void TranslateInfoBarDelegate::UpdateOriginalLanguage(
     const std::string& language_code) {
   ui_delegate_.UpdateOriginalLanguage(language_code);
 }
 
 void TranslateInfoBarDelegate::UpdateTargetLanguage(
     const std::string& language_code) {
   ui_delegate_.UpdateTargetLanguage(language_code);
 }
 
@@ skipping 248 matching lines @@
   TranslationDeclined();
   UMA_HISTOGRAM_BOOLEAN("Translate.DeclineTranslateCloseInfobar", true);
 }
 
 TranslateInfoBarDelegate*
     TranslateInfoBarDelegate::AsTranslateInfoBarDelegate() {
   return this;
 }
 
 }  // namespace translate