Update parse_and_expand_globlist for Windows

crrev.com/c/4220405 updated filelist handling but caused presubmit
failures on Windows due to slash/backslash differences. This change
replaces backslashes with slashes in two critical places so that the
presubmit works correctly.

This was found by the Windows presubmit --all builder:
  https://ci.chromium.org/ui/p/chromium/builders/ci/win-presubmit/198/blamelist

This was tested with:
  git cl presubmit --force --files components\history\core\browser\unit_tests_bundle_data.filelist -v

This change also fixes the writing of filelists on Windows, which was
previously writing \r\n line endings.

Bug: 698042
Change-Id: I5a0daba1ab0a6590288adde5202b619eab2c4c5f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4222293
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Bruce Dawson <brucedawson@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1101274}

build/ios/update_bundle_filelist.py

@@ -112,10 +112,12 @@ def parse_and_expand_globlist(globlist_name, glob_root):
         expansion = [f[prefix_size:] for f in expansion]
 
         if is_exclusion:
-          files = [f for f in files if f not in expansion]
+          files = [f for f in files if f.replace('\\', '/') not in expansion]
         else:
           files += expansion
 
+      # Handle Windows backslashes
+      files = [f.replace('\\', '/') for f in files]
       files.sort()
       return files
 
@@ -137,7 +139,7 @@ def compare_lists(a, b, verbose):
 
 def write_filelist(filelist_name, files, header):
   try:
-    with open(filelist_name, 'w') as filelist:
+    with open(filelist_name, 'w', encoding='utf-8', newline='') as filelist:
       if not _HEADER_PATTERN.search(header):
         header = _HEADER
       filelist.write(header)