pkg-config-wrapper: use system_libdir for libpath

We already have a variable for tracking the system libdir name in the
gyp files, so let's use that instead of hardcoding the logic based on
the arch.

BUG=chromium:219015
TEST=`cbuildbot amd64-generic-tot-chrome-pfq-informational` works

Review URL: https://codereview.chromium.org/244593002

git-svn-id: http://src.chromium.org/svn/trunk/src/build@272792 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

linux/pkg-config-wrapper

@@ -19,18 +19,20 @@ root="$1"
 shift
 target_arch="$1"
 shift
+libpath="$1"
+shift
 
 if [ -z "$root" -o -z "$target_arch" ]
 then
-  echo "usage: $0 /path/to/sysroot target_arch [pkg-config-arguments] package" >&2
+  echo "usage: $0 /path/to/sysroot target_arch libdir [pkg-config-arguments] package" >&2
   exit 1
 fi
 
 if [ "$target_arch" = "x64" ]
 then
-  libpath="lib64"
+  : ${libpath:="lib64"}
 else
-  libpath="lib"
+  : ${libpath:="lib"}
 fi
 
 rewrite=`dirname $0`/rewrite_dirs.py

linux/system.gyp

@@ -6,7 +6,7 @@
   'variables': {
     'conditions': [
       ['sysroot!=""', {
-        'pkg-config': '<(chroot_cmd) ./pkg-config-wrapper "<(sysroot)" "<(target_arch)"',
+        'pkg-config': '<(chroot_cmd) ./pkg-config-wrapper "<(sysroot)" "<(target_arch)" "<(system_libdir)"',
         # libgcrypt-config-wrapper invokes libgcrypt-config directly from the 
         # sysroot, so there's no need to prefix it with <(chroot_cmd).
         'libgcrypt-config': './libgcrypt-config-wrapper "<(sysroot)"',