repo_roller: Remove new_revision property

Remove the never-used new_revision property.

No changes to generated files.

Change-Id: Ia951598b0b6bb0640c1c487e4fa3bbcf2d5c3df5
Reviewed-on: https://pigweed-review.googlesource.com/c/infra/recipes/+/77502
Reviewed-by: Ted Pudlik <tpudlik@google.com>
Commit-Queue: Rob Mohr <mohrr@google.com>
diff --git a/recipes/repo_roller.py b/recipes/repo_roller.py
index ab92d05..440cac2 100644
--- a/recipes/repo_roller.py
+++ b/recipes/repo_roller.py
@@ -65,7 +65,6 @@
 
 def RunSteps(api, props):  # pylint: disable=invalid-name
     path_to_update = str(props.path_to_update)
-    new_revision = str(props.new_revision) or None
     dry_run = props.dry_run
     cc_authors_on_rolls = props.cc_authors_on_rolls
     cc_reviewers_on_rolls = props.cc_reviewers_on_rolls
@@ -78,15 +77,15 @@
     api.checkout(use_trigger=False)
     filepath = api.checkout.root.join(api.checkout.manifest_file)
 
-    # If new_revision wasn't supplied in a property try to get it from the
-    # trigger. If it's not in the trigger it will be retrieved later.
+    new_revision = None
+
+    # Try to get new_revision from the trigger.
     bb_remote = None
-    if new_revision is None:
-        commit = api.buildbucket.build.input.gitiles_commit
-        if commit and commit.project:
-            new_revision = commit.id
-            host = commit.host
-            bb_remote = 'https://{}/{}'.format(host, commit.project)
+    commit = api.buildbucket.build.input.gitiles_commit
+    if commit and commit.project:
+        new_revision = commit.id
+        host = commit.host
+        bb_remote = 'https://{}/{}'.format(host, commit.project)
 
     tree = _TreeBuilder()
     parser = xml.etree.ElementTree.XMLParser(target=tree)
@@ -163,11 +162,11 @@
     else:
         proj_branch = 'main'
 
-    # If we still don't have a revision then it wasn't in the properties nor in
-    # the trigger. (Perhaps this was manually triggered.) In this case we need
-    # to determine the latest revision of this repository. The use_trigger flag
-    # should have no effect but using it to be explicit. Checking out even if
-    # not needed so commit messages can be collected later.
+    # If we still don't have a revision then it wasn't in the trigger. (Perhaps
+    # this was manually triggered.) In this case we need to determine the
+    # latest revision of this repository. The use_trigger flag should have no
+    # effect but using it to be explicit. Checking out even if not needed so
+    # commit messages can be collected later.
     proj_dir = api.path['start_dir'].join('project')
     api.checkout(
         manifest_remote, branch=proj_branch, root=proj_dir, use_trigger=False