Move download stuff to download tab helper.

chrome/browser/ui/download/download_tab_helper_delegate.h

+// Copyright (c) 2011 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_UI_DOWNLOAD_DOWNLOAD_TAB_HELPER_DELEGATE_H_
+#define CHROME_BROWSER_UI_DOWNLOAD_DOWNLOAD_TAB_HELPER_DELEGATE_H_
+#pragma once
+
+#include "base/basictypes.h"
+
+class DownloadItem;
+class TabContentsWrapper;
+
+// Objects implement this interface to get notified about changes in the
+// DownloadTabHelper and to provide necessary functionality.
+class DownloadTabHelperDelegate {
+ public:
+  virtual bool CanDownload(int request_id) = 0;
+
+  virtual void OnStartDownload(DownloadItem* download,
+                               TabContentsWrapper* tab) = 0;
+
+ protected:
+  virtual ~DownloadTabHelperDelegate();
+};
+
+#endif  // CHROME_BROWSER_UI_DOWNLOAD_DOWNLOAD_TAB_HELPER_DELEGATE_H_