Handle CreateFile() trimming trailing dots and spaces in downloads.

BUG=37007
TEST=unit_tests --gtest_filter=DownloadManagerTest.*

Review URL: http://codereview.chromium.org/660297

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@40479 0039d316-1c4b-4281-b951-d872f2087c98
inline bool IsHostCharDigit(char c) {
  return (c >= '0') && (c <= '9');
}

inline bool IsHostCharDigit(char c) {
  return (c >= '0') && (c <= '9');
}
