Better handling of goma inside chroot environment.

build/install-chroot.sh

Index: build/install-chroot.sh
diff --git a/build/install-chroot.sh b/build/install-chroot.sh
index 2b523cba6ae44916fa3168ac898fb9d2c634f43b..ae97d539d054eef5681c3df16bd5f4dc9a60dd30 100755
--- a/build/install-chroot.sh
+++ b/build/install-chroot.sh
@@ -504,6 +504,10 @@ done
 session="$(schroot -c "${chroot}" -b)"
 export CHROOT_SESSION_ID="${session}"
 
+# Set GOMA_TMP_DIR for better handling of goma inside chroot.
+export GOMA_TMP_DIR="/tmp/goma_tmp_$CHROOT_SESSION_ID"
+mkdir -p "$GOMA_TMP_DIR"
+
 if [ $# -eq 0 ]; then
   # Run an interactive shell session
   schroot -c "${session}" -r -p
@@ -554,6 +558,8 @@ done
 # clean up the stale files by invoking us with "--clean" after having killed
 # all running processes.
 schroot -c "${session}" -e
+# Since no goma processes are running, we can remove goma directory.
+rm -rf "$GOMA_TMP_DIR"
 exit $rc
 EOF
 sudo chown root:root /usr/local/bin/"${target%bit}"