Revert 200603 &quotMake Windows traversal checking handle pathologic...&quot

      Seems to have broken base_unittests on Linux ASAN.

> Make Windows traversal checking handle pathological cases 
> 
> Different versions of Windows have undocumented quirks in handling path components 
> (e.g. truncating or ignoring certain leading or trailing characters). In order to avoid potential 
> security bugs we're going to treat components more loosely and risk a few unlikely false 
> positives from FilePath::ReferencesParent(). 
> 
> BUG=181617
> R=brettw@chromium.org, ericu@chromium.org
> 
> Review URL: https://codereview.chromium.org/12771015

TBR=jschuh@chromium.org

Review URL: https://codereview.chromium.org/15095015

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@200610 0039d316-1c4b-4281-b951-d872f2087c98