Reformat python files checked by pylint (part 1/2).

After recently changing .pylintrc (see [1]) we discovered that
the presubmit check always checks all the python files when just
one python file gets updated.

This CL moves all these files one step closer to what the linter
wants.

Autogenerated with:

# Added all the files under pylint control to ~/Desktop/to-reformat
cat ~/Desktop/to-reformat | xargs sed -i '1i\\'
git cl format --python --full

This is part 1 out of 2. The second part will fix function names and
will not be automated.

[1] - https://webrtc-review.googlesource.com/c/src/+/186664

No-Presubmit: True
Bug: webrtc:12114
Change-Id: Idfec4d759f209a2090440d0af2413a1ddc01b841
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/190980
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#32530}
diff --git a/tools_webrtc/gn_check_autofix.py b/tools_webrtc/gn_check_autofix.py
index 57ea0f6..282dc4f 100644
--- a/tools_webrtc/gn_check_autofix.py
+++ b/tools_webrtc/gn_check_autofix.py
@@ -7,7 +7,6 @@
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
-
 """
 This tool tries to fix (some) errors reported by `gn gen --check` or
 `gn check`.
@@ -31,72 +30,78 @@
 
 SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
 
-CHROMIUM_DIRS = ['base', 'build', 'buildtools',
-                 'testing', 'third_party', 'tools']
+CHROMIUM_DIRS = [
+    'base', 'build', 'buildtools', 'testing', 'third_party', 'tools'
+]
 
 TARGET_RE = re.compile(
     r'(?P<indentation_level>\s*)\w*\("(?P<target_name>\w*)"\) {$')
 
+
 class TemporaryDirectory(object):
-  def __init__(self):
-    self._closed = False
-    self._name = None
-    self._name = tempfile.mkdtemp()
+    def __init__(self):
+        self._closed = False
+        self._name = None
+        self._name = tempfile.mkdtemp()
 
-  def __enter__(self):
-    return self._name
+    def __enter__(self):
+        return self._name
 
-  def __exit__(self, exc, value, _tb):
-    if self._name and not self._closed:
-      shutil.rmtree(self._name)
-      self._closed = True
+    def __exit__(self, exc, value, _tb):
+        if self._name and not self._closed:
+            shutil.rmtree(self._name)
+            self._closed = True
 
 
 def Run(cmd):
-  print 'Running:', ' '.join(cmd)
-  sub = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
-  return sub.communicate()
+    print 'Running:', ' '.join(cmd)
+    sub = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    return sub.communicate()
+
 
 def FixErrors(filename, missing_deps, deleted_sources):
-  with open(filename) as f:
-    lines = f.readlines()
+    with open(filename) as f:
+        lines = f.readlines()
 
-  fixed_file = ''
-  indentation_level = None
-  for line in lines:
-    match = TARGET_RE.match(line)
-    if match:
-      target = match.group('target_name')
-      if target in missing_deps:
-        indentation_level = match.group('indentation_level')
-    elif indentation_level is not None:
-      match = re.match(indentation_level + '}$', line)
-      if match:
-        line = ('deps = [\n' +
-                ''.join('  "' + dep + '",\n' for dep in missing_deps[target]) +
-                ']\n') + line
-        indentation_level = None
-      elif line.strip().startswith('deps'):
-        is_empty_deps = line.strip() == 'deps = []'
-        line = 'deps = [\n' if is_empty_deps else line
-        line += ''.join('  "' + dep + '",\n' for dep in missing_deps[target])
-        line += ']\n' if is_empty_deps else ''
-        indentation_level = None
+    fixed_file = ''
+    indentation_level = None
+    for line in lines:
+        match = TARGET_RE.match(line)
+        if match:
+            target = match.group('target_name')
+            if target in missing_deps:
+                indentation_level = match.group('indentation_level')
+        elif indentation_level is not None:
+            match = re.match(indentation_level + '}$', line)
+            if match:
+                line = ('deps = [\n' + ''.join('  "' + dep + '",\n'
+                                               for dep in missing_deps[target])
+                        + ']\n') + line
+                indentation_level = None
+            elif line.strip().startswith('deps'):
+                is_empty_deps = line.strip() == 'deps = []'
+                line = 'deps = [\n' if is_empty_deps else line
+                line += ''.join('  "' + dep + '",\n'
+                                for dep in missing_deps[target])
+                line += ']\n' if is_empty_deps else ''
+                indentation_level = None
 
-    if line.strip() not in deleted_sources:
-      fixed_file += line
+        if line.strip() not in deleted_sources:
+            fixed_file += line
 
-  with open(filename, 'w') as f:
-    f.write(fixed_file)
+    with open(filename, 'w') as f:
+        f.write(fixed_file)
 
-  Run(['gn', 'format', filename])
+    Run(['gn', 'format', filename])
+
 
 def FirstNonEmpty(iterable):
-  """Return first item which evaluates to True, or fallback to None."""
-  return next((x for x in iterable if x), None)
+    """Return first item which evaluates to True, or fallback to None."""
+    return next((x for x in iterable if x), None)
+
 
 def Rebase(base_path, dependency_path, dependency):
-  """Adapt paths so they work both in stand-alone WebRTC and Chromium tree.
+    """Adapt paths so they work both in stand-alone WebRTC and Chromium tree.
 
   To cope with varying top-level directory (WebRTC VS Chromium), we use:
     * relative paths for WebRTC modules.
@@ -113,77 +118,82 @@
     Full target path (E.g. '../rtc_base/time:timestamp_extrapolator').
   """
 
-  root = FirstNonEmpty(dependency_path.split('/'))
-  if root in CHROMIUM_DIRS:
-    # Chromium paths must remain absolute. E.g. //third_party//abseil-cpp...
-    rebased = dependency_path
-  else:
-    base_path = base_path.split(os.path.sep)
-    dependency_path = dependency_path.split(os.path.sep)
+    root = FirstNonEmpty(dependency_path.split('/'))
+    if root in CHROMIUM_DIRS:
+        # Chromium paths must remain absolute. E.g. //third_party//abseil-cpp...
+        rebased = dependency_path
+    else:
+        base_path = base_path.split(os.path.sep)
+        dependency_path = dependency_path.split(os.path.sep)
 
-    first_difference = None
-    shortest_length = min(len(dependency_path), len(base_path))
-    for i in range(shortest_length):
-      if dependency_path[i] != base_path[i]:
-        first_difference = i
-        break
+        first_difference = None
+        shortest_length = min(len(dependency_path), len(base_path))
+        for i in range(shortest_length):
+            if dependency_path[i] != base_path[i]:
+                first_difference = i
+                break
 
-    first_difference = first_difference or shortest_length
-    base_path = base_path[first_difference:]
-    dependency_path = dependency_path[first_difference:]
-    rebased = os.path.sep.join((['..'] * len(base_path)) + dependency_path)
-  return rebased + ':' + dependency
+        first_difference = first_difference or shortest_length
+        base_path = base_path[first_difference:]
+        dependency_path = dependency_path[first_difference:]
+        rebased = os.path.sep.join((['..'] * len(base_path)) + dependency_path)
+    return rebased + ':' + dependency
+
 
 def main():
-  deleted_sources = set()
-  errors_by_file = defaultdict(lambda: defaultdict(set))
+    deleted_sources = set()
+    errors_by_file = defaultdict(lambda: defaultdict(set))
 
-  with TemporaryDirectory() as tmp_dir:
-    mb_script_path = os.path.join(SCRIPT_DIR, 'mb', 'mb.py')
-    mb_config_file_path = os.path.join(SCRIPT_DIR, 'mb', 'mb_config.pyl')
-    mb_gen_command = ([
-        mb_script_path, 'gen',
-        tmp_dir,
-        '--config-file', mb_config_file_path,
-    ] + sys.argv[1:])
+    with TemporaryDirectory() as tmp_dir:
+        mb_script_path = os.path.join(SCRIPT_DIR, 'mb', 'mb.py')
+        mb_config_file_path = os.path.join(SCRIPT_DIR, 'mb', 'mb_config.pyl')
+        mb_gen_command = ([
+            mb_script_path,
+            'gen',
+            tmp_dir,
+            '--config-file',
+            mb_config_file_path,
+        ] + sys.argv[1:])
 
-  mb_output = Run(mb_gen_command)
-  errors = mb_output[0].split('ERROR')[1:]
+    mb_output = Run(mb_gen_command)
+    errors = mb_output[0].split('ERROR')[1:]
 
-  if mb_output[1]:
-    print mb_output[1]
-    return 1
+    if mb_output[1]:
+        print mb_output[1]
+        return 1
 
-  for error in errors:
-    error = error.splitlines()
-    target_msg = 'The target:'
-    if target_msg not in error:
-      target_msg = 'It is not in any dependency of'
-    if target_msg not in error:
-      print '\n'.join(error)
-      continue
-    index = error.index(target_msg) + 1
-    path, target = error[index].strip().split(':')
-    if error[index+1] in ('is including a file from the target:',
-                          'The include file is in the target(s):'):
-      dep = error[index+2].strip()
-      dep_path, dep = dep.split(':')
-      dep = Rebase(path, dep_path, dep)
-      # Replacing /target:target with /target
-      dep = re.sub(r'/(\w+):(\1)$', r'/\1', dep)
-      path = os.path.join(path[2:], 'BUILD.gn')
-      errors_by_file[path][target].add(dep)
-    elif error[index+1] == 'has a source file:':
-      deleted_file = '"' + os.path.basename(error[index+2].strip()) + '",'
-      deleted_sources.add(deleted_file)
-    else:
-      print '\n'.join(error)
-      continue
+    for error in errors:
+        error = error.splitlines()
+        target_msg = 'The target:'
+        if target_msg not in error:
+            target_msg = 'It is not in any dependency of'
+        if target_msg not in error:
+            print '\n'.join(error)
+            continue
+        index = error.index(target_msg) + 1
+        path, target = error[index].strip().split(':')
+        if error[index + 1] in ('is including a file from the target:',
+                                'The include file is in the target(s):'):
+            dep = error[index + 2].strip()
+            dep_path, dep = dep.split(':')
+            dep = Rebase(path, dep_path, dep)
+            # Replacing /target:target with /target
+            dep = re.sub(r'/(\w+):(\1)$', r'/\1', dep)
+            path = os.path.join(path[2:], 'BUILD.gn')
+            errors_by_file[path][target].add(dep)
+        elif error[index + 1] == 'has a source file:':
+            deleted_file = '"' + os.path.basename(
+                error[index + 2].strip()) + '",'
+            deleted_sources.add(deleted_file)
+        else:
+            print '\n'.join(error)
+            continue
 
-  for path, missing_deps in errors_by_file.items():
-    FixErrors(path, missing_deps, deleted_sources)
+    for path, missing_deps in errors_by_file.items():
+        FixErrors(path, missing_deps, deleted_sources)
 
-  return 0
+    return 0
+
 
 if __name__ == '__main__':
-  sys.exit(main())
+    sys.exit(main())