Normalize both histograms paths before comparing

Besides normalizing the histograms paths in the index file, we also need
to normalize all paths in the |histogram_paths.HISTOGRAMS_XMLS_RELATIVE|
because it contains a hardcode path.

Change-Id: I820de86efc7b816c0dba52e42838cbc55b5319c7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2386837
Commit-Queue: Weilun Shi <sweilun@chromium.org>
Auto-Submit: Weilun Shi <sweilun@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Cr-Commit-Position: refs/heads/master@{#803406}

tools/metrics/histograms/print_histogram_names.py

@@ -30,7 +30,7 @@ def get_names(xml_files):
   doc = merge_xml.MergeFiles(files=xml_files)
   histograms, had_errors = extract_histograms.ExtractHistogramsFromDom(doc)
   if had_errors:
-    raise Error("Error parsing inputs.")
+    raise ValueError("Error parsing inputs.")
   return extract_histograms.ExtractNames(histograms)
 
 
@@ -61,8 +61,10 @@ def get_diff(revision):
 
   current_histogram_names = set(get_names(histogram_xml_files()))
   prev_histogram_names = set(
-      get_names(
-          [get_file_at_revision(p) for p in histogram_paths.ALL_XMLS_RELATIVE]))
+      get_names([
+          get_file_at_revision(os.path.normpath(p))
+          for p in histogram_paths.ALL_XMLS_RELATIVE
+      ]))
 
   added_names = sorted(list(current_histogram_names - prev_histogram_names))
   removed_names = sorted(list(prev_histogram_names - current_histogram_names))

tools/metrics/histograms/validate_histograms_index.py

@@ -18,7 +18,10 @@ def main():
   exit_code = 0
   with open(histogram_paths.HISTOGRAMS_INDEX, 'r') as f:
     histograms_paths = [os.path.normpath(line.strip()) for line in f]
-    if histograms_paths != histogram_paths.HISTOGRAMS_XMLS_RELATIVE:
+    new_histograms_paths = [
+        os.path.normpath(p) for p in histogram_paths.HISTOGRAMS_XMLS_RELATIVE
+    ]
+    if histograms_paths != new_histograms_paths:
       exit_code = 1
       logging.error(
         'histograms_index.txt is not up-to-date. Please run '
@@ -28,4 +31,4 @@ def main():
 
 
 if __name__ == '__main__':
-  main()
+  main()
\ No newline at end of file