Add human friendly payload information to the manifest.

This adds new strings to the payload manifest that describe what images
the payload updates from/to. These strings are passed in when delta_generator
is invoked, and are trusted implicitly.

BUG=chromium:226310
TEST=Built/Updated.

Change-Id: I278137c97cf8376d4e2fd8e82402cbb7d4f1a104
Reviewed-on: https://gerrit.chromium.org/gerrit/47347
Reviewed-by: Gilad Arnold <garnold@chromium.org>
Tested-by: Don Garrett <dgarrett@chromium.org>
Commit-Queue: Don Garrett <dgarrett@chromium.org>
diff --git a/delta_diff_generator.h b/delta_diff_generator.h
index c258a58..aec403a 100644
--- a/delta_diff_generator.h
+++ b/delta_diff_generator.h
@@ -76,6 +76,8 @@
                                       const std::string& private_key_path,
                                       off_t chunk_size,
                                       size_t rootfs_partition_size,
+                                      const ImageInfo* old_image_info,
+                                      const ImageInfo* new_image_info,
                                       uint64_t* metadata_size);
 
   // These functions are public so that the unit tests can access them: