Respect debug flag setting when building unit tests.

cros_run_unit_tests

Index: cros_run_unit_tests
diff --git a/cros_run_unit_tests b/cros_run_unit_tests
index 220ad97d23867c5fb535826af113a5369e3bf8d4..3206f0c706272951469fe28a4dc6d34555dd10be 100755
--- a/cros_run_unit_tests
+++ b/cros_run_unit_tests
@@ -23,6 +23,8 @@ DEFINE_string package_file "" \
   "File with space-separated list of packages to run unit tests" f
 DEFINE_string packages "" \
   "Optional space-separated list of packages to run unit tests" p
+DEFINE_boolean withdebug "${FLAGS_TRUE}" \
+  "Build debug versions of Chromium-OS-specific packages."
 
 # Total count of packages with unit tests.
 TEST_COUNT=0
@@ -76,6 +78,10 @@ fi
 
 BLACK_LIST_FILE="$(dirname "$0")/unit_test_black_list.txt"
 
+if [ "${FLAGS_withdebug}" -eq "${FLAGS_FALSE}" ]; then
+  export USE="${USE} -cros-debug"
+fi
+
 for package in ${PACKAGE_LIST}; do
   if grep -xq "${package}" "${BLACK_LIST_FILE}"; then
     warn "Skipping package ${package} since it is blacklisted."