Fix a few typos and style in checkdeps

tools/checkdeps/checkdeps.py

 #!/usr/bin/env python
 # 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.
 
 """Makes sure that files include headers from allowed directories.
 
 Checks DEPS files in the source tree for rules, and applies those rules to
 "#include" and "import" directives in the .cpp and .java source files.
 Any source file including something not permitted by the DEPS files will fail.
@@ skipping 15 matching lines @@
 
 
 def _IsTestFile(filename):
   """Does a rudimentary check to try to skip test files; this could be
   improved but is good enough for now.
   """
   return re.match('(test|mock|dummy)_.*|.*_[a-z]*test\.(cc|mm|java)', filename)
 
 
 class DepsChecker(DepsBuilder):
-  """Parses include_rules from DEPS files and erifies files in the
+  """Parses include_rules from DEPS files and verifies files in the
   source tree against them.
   """
 
   def __init__(self,
                base_directory=None,
                verbose=False,
                being_tested=False,
                ignore_temp_rules=False,
                skip_tests=False):
     """Creates a new DepsChecker.
@@ skipping 29 matching lines @@
     """
     java = java_checker.JavaChecker(self.base_directory, self.verbose)
     cpp = cpp_checker.CppChecker(self.verbose)
     checkers = dict(
         (extension, checker)
         for checker in [java, cpp] for extension in checker.EXTENSIONS)
     self._CheckDirectoryImpl(checkers, start_dir)
 
   def _CheckDirectoryImpl(self, checkers, dir_name):
     rules = self.GetDirectoryRules(dir_name)
-    if rules == None:
+    if rules is None:
       return
 
     # Collect a list of all files and directories to check.
     files_to_check = []
     dirs_to_check = []
     contents = sorted(os.listdir(dir_name))
     for cur in contents:
       full_name = os.path.join(dir_name, cur)
       if os.path.isdir(full_name):
         dirs_to_check.append(full_name)
@@ skipping 21 matching lines @@
 
     Return:
       A list of tuples, (bad_file_path, rule_type, rule_description)
       where rule_type is one of Rule.DISALLOW or Rule.TEMP_ALLOW and
       rule_description is human-readable. Empty if no problems.
     """
     cpp = cpp_checker.CppChecker(self.verbose)
     problems = []
     for file_path, include_lines in added_includes:
       if not cpp.IsCppFile(file_path):
-        pass
+        continue
       rules_for_file = self.GetDirectoryRules(os.path.dirname(file_path))
-      if rules_for_file:
-        for line in include_lines:
-          is_include, violation = cpp.CheckLine(
-              rules_for_file, line, file_path, True)
-          if violation:
-            rule_type = violation.violated_rule.allow
-            if rule_type != Rule.ALLOW:
-              violation_text = results.NormalResultsFormatter.FormatViolation(
-                  violation, self.verbose)
-              problems.append((file_path, rule_type, violation_text))
+      if not rules_for_file:
+        continue
+      for line in include_lines:
+        is_include, violation = cpp.CheckLine(
+            rules_for_file, line, file_path, True)
+        if not violation:
+          continue
+        rule_type = violation.violated_rule.allow
+        if rule_type == Rule.ALLOW:
+          continue
+        violation_text = results.NormalResultsFormatter.FormatViolation(
+            violation, self.verbose)
+        problems.append((file_path, rule_type, violation_text))
     return problems
 
 
 def PrintUsage():
   print """Usage: python checkdeps.py [--root <root>] [tocheck]
 
   --root ROOT Specifies the repository root. This defaults to "../../.."
               relative to the script file. This will be correct given the
               normal location of the script in "<root>/tools/checkdeps".
 
@@ skipping 75 matching lines @@
   if options.json:
     deps_checker.results_formatter = results.JSONResultsFormatter(
         options.json, deps_checker.results_formatter)
 
   deps_checker.CheckDirectory(start_dir)
   return deps_checker.Report()
 
 
 if '__main__' == __name__:
   sys.exit(main())