Fix a typo in PRESUBMIT.py and sort the histograms index

Fix a typo in PRESUBMIT.py and sort th |HISTOGRAMS_XMLS_RELATIVE|
because different OSes have different file system which introduces
non-deterministic into the output of _FindHistogramsXmlFiles() .

Bug: 1116807
Change-Id: I8ff36de29464d388f012864155028a77fdb44e6b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2372775Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Commit-Queue: Alexei Svitkine <asvitkine@chromium.org>
Auto-Submit: Weilun Shi <sweilun@chromium.org>
Cr-Commit-Position: refs/heads/master@{#801465}

tools/metrics/histograms/PRESUBMIT.py

@@ -61,7 +61,7 @@ def GetValidateHistogramsError(input_api, output_api, cwd, results):
   if exit_code != 0:
     error_msg = (
         'Histograms index file is not up-to-date. Please run '
-        '%s/histogram_path.py to update it' % cwd)
+        '%s/histogram_paths.py to update it' % cwd)
     results.append(output_api.PresubmitError(error_msg))
 
 

tools/metrics/histograms/histogram_paths.py

@@ -23,7 +23,7 @@ def _FindHistogramsXmlFiles():
           os.path.join(dirName, filename), PATH_TO_HISTOGRAMS_XML_DIR)
         file_list.append(
             os.path.join('tools/metrics/histograms/histograms_xml', file_path))
-  return file_list
+  return sorted(file_list)
 
 
 ENUMS_XML_RELATIVE = 'tools/metrics/histograms/enums.xml'

tools/metrics/histograms/histograms_index.txt

 tools/metrics/histograms/histograms.xml
-tools/metrics/histograms/histograms_xml/histogram_suffixes.xml
 tools/metrics/histograms/histograms_xml/Fingerprint/histograms.xml
 tools/metrics/histograms/histograms_xml/UMA/histograms.xml
+tools/metrics/histograms/histograms_xml/histogram_suffixes.xml
\ No newline at end of file