Truncate the download file name if it exceeds the filesystem limit.

base/sys_info.h

 // Copyright (c) 2012 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 BASE_SYS_INFO_H_
 #define BASE_SYS_INFO_H_
 
 #include <string>
 
 #include "base/base_export.h"
@@ skipping 17 matching lines @@
 
   // Return the number of megabytes of physical memory on the current machine.
   static int AmountOfPhysicalMemoryMB() {
     return static_cast<int>(AmountOfPhysicalMemory() / 1024 / 1024);
   }
 
   // Return the available disk space in bytes on the volume containing |path|,
   // or -1 on failure.
   static int64 AmountOfFreeDiskSpace(const FilePath& path);
 
+  // Return the maximum length of path component on the volume containing
+  // |path| in the number of FilePath::CharType, or -1 on failure.
+  static int GetMaximumPathComponentLength(const FilePath& path);
+
   // Returns system uptime in milliseconds.
   static int64 Uptime();
 
   // Returns the name of the host operating system.
   static std::string OperatingSystemName();
 
   // Returns the version of the host operating system.
   static std::string OperatingSystemVersion();
 
   // Retrieves detailed numeric values for the OS version.
@@ skipping 55 matching lines @@
   // Returns the device's name.
   static std::string GetDeviceName();
 
   static int DalvikHeapSizeMB();
 #endif  // defined(OS_ANDROID)
 };
 
 }  // namespace base
 
 #endif  // BASE_SYS_INFO_H_