web_dev_style: Fix errors in new directories and enable PRESUBMIT

tools/web_dev_style/css_checker.py

 # Copyright 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.
 
 """Presubmit script for Chromium WebUI resources.
 
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
 for more details about the presubmit API built into depot_tools, and see
 https://chromium.googlesource.com/chromium/src/+/master/styleguide/web/web.md
 for the rules we're checking against here.
@@ skipping 82 matching lines @@
           {\s*\S+\s*  # selector { with stuff after it
           $           # must be at the end of a line
           """,
           re.VERBOSE)
       return brace_space_reg.search(line)
 
     def classes_use_dashes(line):
       # Intentionally dumbed down version of CSS 2.1 grammar for class without
       # non-ASCII, escape chars, or whitespace.
       class_reg = re.compile(r"""
-          \.(-?[\w-]+).*  # ., then maybe -, then alpha numeric and -
-          [,{]\s*$        # selectors should end with a , or {
+          (?<!')\.(-?[\w-]+).*  # ., then maybe -, then alpha numeric and -
+          [,{]\s*$              # selectors should end with a , or {
           """,
           re.VERBOSE)
       m = class_reg.search(line)
       if not m:
         return False
       class_name = m.group(1)
       return class_name.lower() != class_name or '_' in class_name
 
     end_mixin_reg = re.compile(r'\s*};\s*$')
 
     def close_brace_on_new_line(line):
       # Ignore single frames in a @keyframe, i.e. 0% { margin: 50px; }
       frame_reg = re.compile(r"""
-          \s*(from|to|\d+%)\s*{   # 50% {
-          \s*[\w-]+:              # rule:
-          (\s*[\w\(\), -]+)+\s*;  # value;
-          \s*}\s*                 # }
+          \s*(from|to|\d+%)\s*{     # 50% {
+          \s*[\w-]+:                # rule:
+          (\s*[\w\(\), -\.]+)+\s*;  # value;
+          \s*}\s*                   # }
           """,
           re.VERBOSE)
       return ('}' in line and re.search(r'[^ }]', line) and
               not frame_reg.match(line) and not end_mixin_reg.match(line))
 
     def colons_have_space_after(line):
       colon_space_reg = re.compile(r"""
           (?<!data)    # ignore data URIs
           :(?!//)      # ignore url(http://), etc.
           \S[^;]+;\s*  # only catch one-line rules for now
@@ skipping 162 matching lines @@
       hsl_reg = re.compile(r"""
           hsl\([^\)]*       # hsl(maybestuff
           (?:[, ]|(?<=\())  # a comma or space not followed by a (
           (?:0?\.?)?0%      # some equivalent to 0%
           """,
           re.VERBOSE)
       zeros_reg = re.compile(r"""
           ^.*(?:^|[^0-9.])              # start/non-number
           (?:\.0|0(?:\.0?               # .0, 0, or 0.0
           |px|em|%|in|cm|mm|pc|pt|ex))  # a length unit
-          (?:\D|$)                      # non-number/end
+          (?!svg|png|jpg)(?:\D|$)       # non-number/end
           (?=[^{}]+?}).*$               # only { rules }
           """,
           re.MULTILINE | re.VERBOSE)
       errors = []
       for z in re.finditer(zeros_reg, contents):
         first_line = z.group(0).strip().splitlines()[0]
         if not hsl_reg.search(first_line):
           errors.append('    ' + first_line)
       return errors
 
@@ skipping 108 matching lines @@
                 error += check['after'](line)
               check_errors.append(error)
           if len(check_errors) > 0:
             file_errors.append('- %s\n%s' %
                 (check['desc'], '\n'.join(check_errors)))
       if file_errors:
         results.append(self.output_api.PresubmitPromptWarning(
             '%s:\n%s' % (f[0], '\n\n'.join(file_errors))))
 
     return results