Pass out_hash_file to delta_generator.

delta_generator now requires out_hash_file flag to be set if
out_metadata_hash_file flag is set, so that it can calculate both hash in
one pass.

BUG=b:25234653
TEST=cros_generate_update_payload --out_metadata_hash_file ...

Change-Id: If5a556717e722fc5a1c0f077aa2b1eebab7eb40d
Reviewed-on: https://chromium-review.googlesource.com/308960
Commit-Ready: Alex Deymo <[email protected]>
Tested-by: Sen Jiang <[email protected]>
Reviewed-by: Alex Deymo <[email protected]>
diff --git a/scripts/brillo_update_payload b/scripts/brillo_update_payload
index 267fcf4..50102c7 100755
--- a/scripts/brillo_update_payload
+++ b/scripts/brillo_update_payload
@@ -403,26 +403,17 @@
     die "Error: you must specify the input unsigned payload with \
 --unsigned_payload FILENAME"
 
-  [[ -n "${FLAGS_metadata_hash_file}" ]] ||
   [[ -n "${FLAGS_payload_hash_file}" ]] ||
-    die "Error: you must specify --metadata_hash_file FILENAME \
-or --payload_hash_file FILENAME"
+    die "Error: you must specify --payload_hash_file FILENAME"
 }
 
 cmd_hash() {
-  if [[ -n "${FLAGS_metadata_hash_file}" ]]; then
-    "${GENERATOR}" \
-        -in_file="${FLAGS_unsigned_payload}" \
-        -signature_size="${FLAGS_signature_size}" \
-        -out_metadata_hash_file="${FLAGS_metadata_hash_file}"
-  fi
+  "${GENERATOR}" \
+      -in_file="${FLAGS_unsigned_payload}" \
+      -signature_size="${FLAGS_signature_size}" \
+      -out_hash_file="${FLAGS_payload_hash_file}" \
+      -out_metadata_hash_file="${FLAGS_metadata_hash_file}"
 
-  if [[ -n "${FLAGS_payload_hash_file}" ]]; then
-    "${GENERATOR}" \
-        -in_file="${FLAGS_unsigned_payload}" \
-        -signature_size="${FLAGS_signature_size}" \
-        -out_hash_file="${FLAGS_payload_hash_file}"
-  fi
   echo "Done generating hash."
 }