Add support for git_hyper_blame for Windows

Change-Id: I8cfbc013b4f17d727b65313e9e4823bab5d9ac18
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2113553
Reviewed-by: Edward Lesmes <ehmaldonado@chromium.org>
Commit-Queue: Josip Sokcevic <sokcevic@google.com>
diff --git a/git_hyper_blame.py b/git_hyper_blame.py
index bd5789a..6a8dae8 100755
--- a/git_hyper_blame.py
+++ b/git_hyper_blame.py
@@ -258,6 +258,7 @@
 def hyper_blame(outbuf, ignored, filename, revision):
   # Map from commit to parsed blame from that commit.
   blame_from = {}
+  filename = os.path.normpath(filename)
 
   def cache_blame_from(filename, commithash):
     try:
@@ -315,7 +316,8 @@
 
     # If any line has a different filename to the file's current name, turn on
     # filename display for the entire blame output.
-    if line.commit.filename != filename:
+    # Use normpath to make variable consistent across platforms.
+    if os.path.normpath(line.commit.filename) != filename:
       show_filenames = True
 
     new_parsed.append(line)