Build gtest from source rather than using SDK-provided version

ports/glibc-compat/build.sh

 # Copyright (c) 2012 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.
 
 BUILD_DIR=${SRC_DIR}
 if [ "${TOOLCHAIN}" != "emscripten" ]; then
   EXECUTABLES=out/glibc_compat_test
 fi
 
 ConfigureStep() {
   LogExecute cp -rf ${START_DIR}/* .
   LogExecute rm -rf out
 }
 
+
 BuildStep() {
   if [ "${TOOLCHAIN}" = "emscripten" ]; then
     return
   fi
   # export the nacl tools
   export CC=${NACLCC}
   export CXX=${NACLCXX}
   export AR=${NACLAR}
   export NACL_SDK_VERSION
   export NACL_SDK_ROOT
   export LDFLAGS=${NACLPORTS_LDFLAGS}
   export CPPFLAGS=${NACLPORTS_CPPFLAGS}
   export CFLAGS=${NACLPORTS_CFLAGS}
+  export GTEST_DIR=${NACL_PREFIX}/src/gtest
   DefaultBuildStep
 }
 
 TestStep() {
   if [ "${TOOLCHAIN}" = "emscripten" ]; then
     return
   fi
   if [ "${TOOLCHAIN}" = "pnacl" ]; then
     RunSelLdrCommand ./out/glibc_compat_test
   else
@@ skipping 14 matching lines @@
   for file in include/*.h ${INCDIR}; do
     if [ -f $file ]; then
       LogExecute install -m 644 $file ${INCDIR}/
     fi
   done
   for dir in sys arpa machine net netinet netinet6; do
     MakeDir ${INCDIR}/${dir}
     LogExecute install -m 644 include/${dir}/*.h ${INCDIR}/${dir}/
   done
 }