Make rebase_path() aware of Windows drive letter capitalization

Make sure rebase_path() supports both capital and non-capital Windows path
drive letters. It's unable to find common path prefix otherwise.

BUG=596072

Review URL: https://codereview.chromium.org/1817533002

Cr-Original-Commit-Position: refs/heads/master@{#382532}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 01a402cd6fb6873e61d2faa269b6b991d307635e
2 files changed
tree: 26ddd999d0dc1346c405289df1acce0f3be5ac81
  1. tools/