Trigger app banner when add to homescreen is pressed and WebAPKs are enabled.

components/infobars/core/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/infobars/core/infobar_delegate.h"
 
 #include "base/logging.h"
 #include "build/build_config.h"
 #include "components/infobars/core/infobar.h"
 #include "components/infobars/core/infobar_manager.h"
@@ skipping 109 matching lines @@
 ThreeDAPIInfoBarDelegate* InfoBarDelegate::AsThreeDAPIInfoBarDelegate() {
   return nullptr;
 }
 
 translate::TranslateInfoBarDelegate*
     InfoBarDelegate::AsTranslateInfoBarDelegate() {
   return nullptr;
 }
 
 #if defined(OS_ANDROID)
+banners::AppBannerInfoBarDelegateAndroid*
+InfoBarDelegate::AsAppBannerInfoBarDelegateAndroid() {
+  return nullptr;
+}
+
 MediaStreamInfoBarDelegateAndroid*
 InfoBarDelegate::AsMediaStreamInfoBarDelegateAndroid() {
   return nullptr;
 }
 
 MediaThrottleInfoBarDelegate*
     InfoBarDelegate::AsMediaThrottleInfoBarDelegate() {
   return nullptr;
 }
 #endif
 
 InfoBarDelegate::InfoBarDelegate() : nav_entry_id_(0) {
 }
 
 }  // namespace infobars