Normalize image/x-png mime type to the standard one

grit/format/html_inline.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Flattens a HTML file by inlining its external resources.
 
 This is a small script that takes a HTML file, looks for src attributes
 and inlines the specified file, producing one HTML file with no external
 dependencies. It recursively inlines the included files.
@@ skipping 29 matching lines @@
 _SRC_RE = lazy_re.compile(
     r'<(?!script)(?:[^>]+?\s)src=(?P<quote>")(?P<filename>[^"\']*)\1',
     re.MULTILINE)
 _ICON_RE = lazy_re.compile(
     r'<link rel="icon"\s(?:[^>]+?\s)?'
     'href=(?P<quote>")(?P<filename>[^"\']*)\1',
     re.MULTILINE)
 
 
 
+def FixupMimeType(mime_type):
+  """Helper function that normalizes platform differences in the mime type
+     returned by the Python's mimetypes.guess_type API.
+  """
+  mappings = {
+    'image/x-png': 'image/png'
+  }
+  return mappings[mime_type] if mime_type in mappings else mime_type
+
+
 def GetDistribution():
   """Helper function that gets the distribution we are building.
 
   Returns:
     string
   """
   distribution = DIST_DEFAULT
   if DIST_ENV_VAR in os.environ.keys():
     distribution = os.environ[DIST_ENV_VAR]
     if len(distribution) > 1 and distribution[0] == '_':
@@ skipping 29 matching lines @@
     # filename is probably a URL, which we don't want to bother inlining
     return src_match.group(0)
 
   filename = filename.replace(DIST_SUBSTR , distribution)
   filepath = os.path.normpath(os.path.join(base_path, filename))
   inlined_files.add(filepath)
 
   if names_only:
     return ""
 
-  mimetype = mimetypes.guess_type(filename)[0] or 'text/plain'
+  mimetype = FixupMimeType(mimetypes.guess_type(filename)[0]) or 'text/plain'
   inline_data = base64.standard_b64encode(util.ReadFile(filepath, util.BINARY))
 
   prefix = src_match.string[src_match.start():src_match.start('filename')]
   suffix = src_match.string[src_match.end('filename'):src_match.end()]
   return '%sdata:%s;base64,%s%s' % (prefix, mimetype, inline_data, suffix)
 
 
 class InlinedData:
   """Helper class holding the results from DoInline().
 
@@ skipping 273 matching lines @@
 
 def main():
   if len(sys.argv) <= 2:
     print "Flattens a HTML file by inlining its external resources.\n"
     print "html_inline.py inputfile outputfile"
   else:
     InlineToFile(sys.argv[1], sys.argv[2], None)
 
 if __name__ == '__main__':
   main()