Allow re-targeting of naclports install

libraries/tinyxml/nacl-tinyxml.sh

 #!/bin/bash
 # Copyright (c) 2011 The Native Client Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 #
 
 # nacl-tinyxml.sh
 #
 # usage:  nacl-tinyxml.sh
 #
@@ skipping 12 matching lines @@
   export AR=${NACLAR}
   export LD=${NACLLD}
   export RANLIB=${NACLRANLIB}
   make clean
   make OUTPUT=libtinyxml.a
 }
 
 
 CustomInstallStep() {
   # copy libs and headers manually
-  Banner "Installing ${PACKAGE_NAME} to ${NACL_SDK_USR}"
-  ChangeDir ${NACL_SDK_USR_INCLUDE}
+  Banner "Installing ${PACKAGE_NAME} to ${NACLPORTS_PREFIX}"
+  ChangeDir ${NACLPORTS_INCLUDE}
   Remove ${PACKAGE_NAME}
   MakeDir ${PACKAGE_NAME}
   readonly THIS_PACKAGE_PATH=${NACL_PACKAGES_REPOSITORY}/${PACKAGE_NAME}
   cp ${THIS_PACKAGE_PATH}/*.h ${PACKAGE_NAME}/
-  ChangeDir ${NACL_SDK_USR_LIB}
+  ChangeDir ${NACLPORTS_LIBDIR}
   cp ${THIS_PACKAGE_PATH}/*.a .
   DefaultTouchStep
 }
 
 
 CustomPackageInstall() {
   DefaultPreInstallStep
   DefaultDownloadStep
   DefaultExtractStep
   DefaultPatchStep
   CustomBuildStep
   CustomInstallStep
   DefaultCleanUpStep
 }
 
 
 CustomPackageInstall
 exit 0