[Downloads] Prevent dangerous files from being opened automatically.

chrome/browser/download/download_extensions.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_DOWNLOAD_DOWNLOAD_EXTENSIONS_H_
 #define CHROME_BROWSER_DOWNLOAD_DOWNLOAD_EXTENSIONS_H_
 
 #include <string>
 
 #include "base/files/file_path.h"
 
 namespace download_util {
 
 enum DownloadDangerLevel {
   NOT_DANGEROUS,
   ALLOW_ON_USER_GESTURE,
   DANGEROUS
 };
 
 // Determine the download danger level of a file.
 DownloadDangerLevel GetFileDangerLevel(const base::FilePath& path);
 
+// Returns true if the file specified by |path| is allowed to open
+// automatically. Most file types can be set to open automatically, but some
+// executable file types may not.
+bool IsAllowedToOpenAutomatically(const base::FilePath& path);
+
 // Tests if we think the server means for this mime_type to be executable.
 bool IsExecutableMimeType(const std::string& mime_type);
 
 }  // namespace download_util
 
 #endif  // CHROME_BROWSER_DOWNLOAD_DOWNLOAD_EXTENSIONS_H_