message: Fix the build error of CI for macOS on GitHub.
diff: @@ -9,7 +9,7 @@ index e038151b..9093c4ee 100755
  # Copyright (c) 2012 Google Inc. All rights reserved.
  # Use of this source code is governed by a BSD-style license that can be
  diff --git a/pylib/gyp/mac_tool.py b/pylib/gyp/mac_tool.py
  -index 64d21063..3b878ddf 100755
  +index 64d21063..c6833157 100755
  --- a/pylib/gyp/mac_tool.py
  +++ b/pylib/gyp/mac_tool.py
  @@ -36,14 +36,15 @@ index 64d21063..3b878ddf 100755
  fp = open(dest, 'wb')
  fp.write(s.decode(input_code).encode('UTF-16'))
  -@@ -169,15 +169,12 @@ class MacTool(object):
  +@@ -169,15 +169,13 @@ class MacTool(object):
  def ExecCopyInfoPlist(self, source, dest, convert_to_binary, *keys):
  """Copies the |source| Info.plist to the destination directory |dest|."""
  # Read the source Info.plist into memory.
  - fd = open(source, 'r')
  - lines = fd.read()
  - fd.close()
  -+ plist = plistlib.load(source)
  ++ with open(source, 'rb') as fp:
  ++ plist = plistlib.load(fp)
  # Insert synthesized key/value pairs (e.g. BuildMachineOSBuild).
  - plist = plistlib.readPlistFromString(lines)
  