Use native implementation of dangerous download infobar

chrome/browser/android/download/dangerous_download_infobar_delegate.h

+// Copyright 2016 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.
+
+#ifndef CHROME_BROWSER_ANDROID_DOWNLOAD_DANGEROUS_DOWNLOAD_INFOBAR_DELEGATE_H_
+#define CHROME_BROWSER_ANDROID_DOWNLOAD_DANGEROUS_DOWNLOAD_INFOBAR_DELEGATE_H_
+
+#include "base/macros.h"
+#include "components/infobars/core/confirm_infobar_delegate.h"
+#include "content/public/browser/download_item.h"
+
+class InfoBarService;
+
+// An infobar that asks if user wants to download a dangerous file.
+// Note that this infobar does not expire if the user subsequently navigates,
+// since such navigations won't automatically cancel the underlying download.
+class DangerousDownloadInfoBarDelegate
+    : public ConfirmInfoBarDelegate,
+      public content::DownloadItem::Observer {
+ public:
+  static void Create(
+      InfoBarService* infobar_service,
+      content::DownloadItem* download_item);
+
+  ~DangerousDownloadInfoBarDelegate() override;
+
+  // content::DownloadItem::Observer:
+  void OnDownloadDestroyed(content::DownloadItem* download_item) override;
+
+ private:
+  explicit DangerousDownloadInfoBarDelegate(
+      content::DownloadItem* download_item);
+
+  // ConfirmInfoBarDelegate:
+  infobars::InfoBarDelegate::InfoBarIdentifier GetIdentifier() const override;
+  int GetIconId() const override;
+  bool ShouldExpire(const NavigationDetails& details) const override;
+  void InfoBarDismissed() override;
+  base::string16 GetMessageText() const override;
+  bool Accept() override;
+  bool Cancel() override;
+
+  // The download item that is requesting the infobar. Could get deleted while
+  // the infobar is showing.
+  content::DownloadItem* download_item_;
+
+  DISALLOW_COPY_AND_ASSIGN(DangerousDownloadInfoBarDelegate);
+};
+
+
+#endif  // CHROME_BROWSER_ANDROID_DOWNLOAD_DANGEROUS_DOWNLOAD_INFOBAR_DELEGATE_H_