implementation for new duplicate download UI

chrome/browser/android/download/duplicate_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_DUPLICATE_DOWNLOAD_INFOBAR_DELEGATE_H_
+#define CHROME_BROWSER_ANDROID_DOWNLOAD_DUPLICATE_DOWNLOAD_INFOBAR_DELEGATE_H_
+
+#include "components/infobars/core/infobar_delegate.h"
+
+class InfoBarService;
+
+namespace chrome {
+namespace android {
+
+// An infobar that asks if user wants to continue downloading when there is
+// already a duplicate file on the sdcard. If user chooses to proceed,

[gone, 2016/11/07 19:45:55]

the sdcard -> in storage?

[qinmin, 2016/11/08 00:30:50]

Done.

+// a new file will be created.
+// Note that this infobar does not expire if the user subsequently navigates,
+// since such navigations won't automatically cancel the underlying download.
+class DuplicateDownloadInfoBarDelegate : public infobars::InfoBarDelegate {

[gone, 2016/11/07 19:45:55]

Make this a ConfirmInfoBarDelegate subclass, then hook Download and Cancel into
ConfirmInfoBarDelegate::Accept() and ConfirmInfoBarDelegate::Cancel().

[qinmin, 2016/11/08 00:30:50]

Done.

+ public:
+  // This is called when the user chooses to download the url.
+  // If handling the operation results in dismissing the infobar, returns false
+  // (i.e. the caller must not dismiss the infobar).
+  virtual bool Download() = 0;
+
+  // This is called when the user chooses to cancel the download.
+  // If handling the operation results in dismissing the infobar, returns false
+  // (i.e. the caller must not dismiss the infobar).
+  virtual bool Cancel() = 0;
+
+  // Gets the file path to be downloaded.
+  virtual std::string GetFilePath() const = 0;
+
+  // Whether the download is for offline page.
+  virtual bool IsOfflinePage() const;
+
+  virtual std::string GetPageURL() const;
+
+  bool ShouldExpire(const NavigationDetails& details) const override;

[gone, 2016/11/07 19:45:55]

DISALLOW_COPY_AND_ASSIGN

[qinmin, 2016/11/08 00:30:50]

This is a pure virtual class, so DISALLOW_COPY_AND_ASSIGN is not needed.

+};
+
+}  // namespace android
+}  // namespace chrome
+
+#endif  // CHROME_BROWSER_ANDROID_DOWNLOAD_DUPLICATE_DOWNLOAD_INFOBAR_DELEGATE_H_