Make Linux GN build's cflags match GYP's

build/config/linux/pkg-config.py

 # Copyright (c) 2013 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.
 
 import json
 import os
 import subprocess
 import sys
 import re
 from optparse import OptionParser
@@ skipping 101 matching lines @@
   for regexp in options.strip_out:
     strip_out.append(re.compile(regexp))
 
 SetConfigPath(options)
 if options.sysroot:
   prefix = GetPkgConfigPrefixToStrip(args)
 else:
   prefix = ''
 
 try:
-  flag_string = subprocess.check_output(["pkg-config", "--cflags", "--libs"] +
+  flag_string = subprocess.check_output(
+      [ "pkg-config", "--cflags", "--libs-only-l", "--libs-only-L" ] +
       args, env=os.environ)
   # For now just split on spaces to get the args out. This will break if
   # pkgconfig returns quoted things with spaces in them, but that doesn't seem
   # to happen in practice.
   all_flags = flag_string.strip().split(' ')
 except:
   print "Could not run pkg-config."
   sys.exit(1)
 
 
@@ skipping 24 matching lines @@
     # this anyway. Removing it here prevents a bunch of duplicate inclusions on
     # the command line.
     pass
   else:
     cflags.append(flag)
 
 # Output a GN array, the first one is the cflags, the second are the libs. The
 # JSON formatter prints GN compatible lists when everything is a list of
 # strings.
 print json.dumps([includes, cflags, libs, lib_dirs, ldflags])