Suggestion: there is some utility functions in the `base/file_util.h` that may be helpful to solve this problem. PTAL: 
```
//-----------------------------------------------------------------------------
// Functions that involve filesystem access or modification:

// Returns an absolute version of a relative path. Returns an empty path on
// error. On POSIX, this function fails if the path does not exist. This
// function can result in I/O so it can be slow.
BASE_EXPORT FilePath MakeAbsoluteFilePath(const FilePath& input);
```

However, I didn't try it so I can't make sure it can work in this situation. 

Another suggestion: change tab to 2 space. I think `node-webkit` is also following [Google C++ Style Guide](http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml).

Hope it can help.