update_engine: Rename signing variables.

Rename 'signatures' to 'payload_signatures' so there is a clear distinction
between metadata and payload signatures and their input files.

BUG=chromium:845614
TEST=payload tryjobs
CQ-DEPEND=CL:1069530

Change-Id: Ic2e924871611af1b1f0ee2f1dfd7c6b9f52decc8
Reviewed-on: https://chromium-review.googlesource.com/1069527
Commit-Ready: Amin Hassani <ahassani@chromium.org>
Tested-by: Amin Hassani <ahassani@chromium.org>
Reviewed-by: Nicolas Norvez <norvez@chromium.org>
Reviewed-by: Xiaochu Liu <xiaochu@chromium.org>
diff --git a/payload_consumer/delta_performer_integration_test.cc b/payload_consumer/delta_performer_integration_test.cc
index 3572a6d..6cdb8df 100644
--- a/payload_consumer/delta_performer_integration_test.cc
+++ b/payload_consumer/delta_performer_integration_test.cc
@@ -283,7 +283,7 @@
 
   ASSERT_EQ(0,
             System(base::StringPrintf(
-                "%s -in_file=%s -signature_file=%s -out_file=%s",
+                "%s -in_file=%s -payload_signature_file=%s -out_file=%s",
                 delta_generator_path.c_str(),
                 payload_path.c_str(),
                 sig_file.c_str(),
diff --git a/payload_generator/generate_delta_main.cc b/payload_generator/generate_delta_main.cc
index a20a567..0cd1d1c 100644
--- a/payload_generator/generate_delta_main.cc
+++ b/payload_generator/generate_delta_main.cc
@@ -150,13 +150,16 @@
   LOG_IF(FATAL, out_file.empty())
       << "Must pass --out_file to sign payload.";
   LOG_IF(FATAL, payload_signature_file.empty())
-      << "Must pass --signature_file to sign payload.";
-  vector<brillo::Blob> signatures, metadata_signatures;
-  SignatureFileFlagToBlobs(payload_signature_file, &signatures);
+      << "Must pass --payload_signature_file to sign payload.";
+  vector<brillo::Blob> payload_signatures, metadata_signatures;
+  SignatureFileFlagToBlobs(payload_signature_file, &payload_signatures);
   SignatureFileFlagToBlobs(metadata_signature_file, &metadata_signatures);
   uint64_t final_metadata_size;
-  CHECK(PayloadSigner::AddSignatureToPayload(in_file, signatures,
-      metadata_signatures, out_file, &final_metadata_size));
+  CHECK(PayloadSigner::AddSignatureToPayload(in_file,
+                                             payload_signatures,
+                                             metadata_signatures,
+                                             out_file,
+                                             &final_metadata_size));
   LOG(INFO) << "Done signing payload. Final metadata size = "
             << final_metadata_size;
   if (!out_metadata_size_file.empty()) {
@@ -311,7 +314,8 @@
                 "You may pass in multiple sizes by colon separating them. E.g. "
                 "2048:2048:4096 will assume 3 signatures, the first two with "
                 "2048 size and the last 4096.");
-  DEFINE_string(signature_file, "",
+  DEFINE_string(payload_signature_file,
+                "",
                 "Raw signature file to sign payload with. To pass multiple "
                 "signatures, use a single argument with a colon between paths, "
                 "e.g. /path/to/sig:/path/to/next:/path/to/last_sig . Each "
@@ -402,9 +406,12 @@
                             FLAGS_out_metadata_hash_file, FLAGS_in_file);
     return 0;
   }
-  if (!FLAGS_signature_file.empty()) {
-    SignPayload(FLAGS_in_file, FLAGS_out_file, FLAGS_signature_file,
-                FLAGS_metadata_signature_file, FLAGS_out_metadata_size_file);
+  if (!FLAGS_payload_signature_file.empty()) {
+    SignPayload(FLAGS_in_file,
+                FLAGS_out_file,
+                FLAGS_payload_signature_file,
+                FLAGS_metadata_signature_file,
+                FLAGS_out_metadata_size_file);
     return 0;
   }
   if (!FLAGS_public_key.empty()) {
diff --git a/scripts/brillo_update_payload b/scripts/brillo_update_payload
index 61ecadf..3802e13 100755
--- a/scripts/brillo_update_payload
+++ b/scripts/brillo_update_payload
@@ -628,7 +628,7 @@
   GENERATOR_ARGS=(
     -in_file="${FLAGS_unsigned_payload}"
     -signature_size="${FLAGS_signature_size}"
-    -signature_file="${FLAGS_payload_signature_file}"
+    -payload_signature_file="${FLAGS_payload_signature_file}"
     -metadata_signature_file="${FLAGS_metadata_signature_file}"
     -out_file="${FLAGS_payload}"
   )