Delete unused Pathname methods.

BUG=webrtc:6424

Review-Url: https://codereview.webrtc.org/2745073004
Cr-Original-Commit-Position: refs/heads/master@{#17388}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 0be49d8d1028a2eb3aafd979091cfa0311e6c3c3
2 files changed