Enable presubmit pylint in build/android.

build/android/gyp/util/build_utils.py

Index: build/android/gyp/util/build_utils.py
diff --git a/build/android/gyp/util/build_utils.py b/build/android/gyp/util/build_utils.py
index 0bf94821f3fa86617446b6a779e3b4ebc37c58ea..165fa244d458048d59137f3709e50ade0c6f0574 100644
--- a/build/android/gyp/util/build_utils.py
+++ b/build/android/gyp/util/build_utils.py
@@ -10,7 +10,6 @@ import shlex
 import shutil
 import subprocess
 import sys
-import traceback
 
 
 def MakeDirectory(dir_path):
@@ -31,18 +30,18 @@ def Touch(path):
     os.utime(path, None)
 
 
-def FindInDirectory(directory, filter):
+def FindInDirectory(directory, filename_filter):
   files = []
-  for root, dirnames, filenames in os.walk(directory):
-    matched_files = fnmatch.filter(filenames, filter)
+  for root, _dirnames, filenames in os.walk(directory):
+    matched_files = fnmatch.filter(filenames, filename_filter)
     files.extend((os.path.join(root, f) for f in matched_files))
   return files
 
 
-def FindInDirectories(directories, filter):
+def FindInDirectories(directories, filename_filter):
   all_files = []
   for directory in directories:
-    all_files.extend(FindInDirectory(directory, filter))
+    all_files.extend(FindInDirectory(directory, filename_filter))
   return all_files
 
 
@@ -56,7 +55,9 @@ def ParseGypList(gyp_string):
   return shlex.split(gyp_string)
 
 
-def CheckOptions(options, parser, required=[]):
+def CheckOptions(options, parser, required=None):
+  if not required:
+    return
   for option_name in required:
     if not getattr(options, option_name):
       parser.error('--%s is required' % option_name.replace('_', '-'))
@@ -83,6 +84,7 @@ class CalledProcessError(Exception):
   exits with a non-zero exit code."""
 
   def __init__(self, cwd, args, output):
+    super(CalledProcessError, self).__init__()
     self.cwd = cwd
     self.args = args
     self.output = output
@@ -129,8 +131,8 @@ def IsTimeStale(output, inputs):
     return True
 
   output_time = GetModifiedTime(output)
-  for input in inputs:
-    if GetModifiedTime(input) > output_time:
+  for i in inputs:
+    if GetModifiedTime(i) > output_time:
       return True
   return False