Allow re-targeting of naclports install

libraries/gtest-1.5.0/nacl-gtest-1.5.0.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-gtest-1.5.0.sh
 #
 # usage:  nacl-gtest-1.5.0.sh
 #
@@ skipping 10 matching lines @@
   export CXX=${NACLCXX}
   export AR=${NACLAR}
   export RANLIB=${NACLRANLIB}
   export PATH=${NACL_BIN_PATH}:${PATH};
   export LIB_GTEST=libgtest.a
 
   ChangeDir ${NACL_PACKAGES_REPOSITORY}/${PACKAGE_NAME}
 }
 
 CustomInstallStep() {
-  Remove ${NACL_SDK_USR_INCLUDE}/gtest
+  Remove ${NACLPORTS_INCLUDE}/gtest
   readonly THIS_PACKAGE_PATH=${NACL_PACKAGES_REPOSITORY}/${PACKAGE_NAME}
-  (ChangeDir include; tar cf - --exclude='gtest-death-test.h' --exclude='gtest-death-test-internal.h' gtest | (ChangeDir ${NACL_SDK_USR_INCLUDE}; tar xfp -))
-  Remove ${NACL_SDK_USR_LIB}/${LIB_GTEST}
-  install -m 644 ${LIB_GTEST} ${NACL_SDK_USR_LIB}/${LIB_GTEST}
+  (ChangeDir include; tar cf - --exclude='gtest-death-test.h' --exclude='gtest-death-test-internal.h' gtest | (ChangeDir ${NACLPORTS_INCLUDE}; tar xfp -))
+  Remove ${NACLPORTS_LIBDIR}/${LIB_GTEST}
+  install -m 644 ${LIB_GTEST} ${NACLPORTS_LIBDIR}/${LIB_GTEST}
   DefaultTouchStep
 }
 
 CustomPackageInstall() {
    DefaultPreInstallStep
    DefaultDownloadStep
    DefaultExtractStep
    DefaultPatchStep
    CustomConfigureStep
    DefaultBuildStep
    CustomInstallStep
    DefaultCleanUpStep
 }
 
 CustomPackageInstall
 exit 0