Add a 'setlabel' command to gerrit_client.py

And add a hook for it in the gerrit recipe_module.

This will allow invocations of gerrit_client to set votes like
"code-review-1" or "commit-queue+1" on CLs. This will be used by bots
to control CLs they just created with update_files().

Bug: 1250084
Change-Id: I888458983165fed5882e5c37cba4a69dbfb9b810
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3207266
Commit-Queue: Ben Pastene <bpastene@chromium.org>
Reviewed-by: Josip Sokcevic <sokcevic@google.com>

recipes/recipe_modules/gerrit/api.py

@@ -226,6 +226,24 @@ class GerritApi(recipe_api.RecipeApi):
         step_test_data=step_test_data,
     ).json.output
 
+  def set_change_label(self,
+                       host,
+                       change,
+                       label_name,
+                       label_value,
+                       name=None,
+                       step_test_data=None):
+    args = [
+        'setlabel', '--host', host, '--change',
+        int(change), '--json_file',
+        self.m.json.output(), '-l', label_name, label_value
+    ]
+    return self(
+        name or 'setlabel',
+        args,
+        step_test_data=step_test_data,
+    ).json.output
+
   def move_changes(self,
                    host,
                    project,

recipes/recipe_modules/gerrit/examples/full.expected/basic.json

@@ -450,6 +450,60 @@
       "@@@STEP_LOG_END@json.output@@@"
     ]
   },
+  {
+    "cmd": [
+      "vpython",
+      "-u",
+      "RECIPE_REPO[depot_tools]/gerrit_client.py",
+      "setlabel",
+      "--host",
+      "https://chromium-review.googlesource.com",
+      "--change",
+      "123",
+      "--json_file",
+      "/path/to/tmp/json",
+      "-l",
+      "code-review",
+      "-1"
+    ],
+    "env": {
+      "PATH": "<PATH>:RECIPE_REPO[depot_tools]"
+    },
+    "infra_step": true,
+    "name": "gerrit setlabel",
+    "~followup_annotations": [
+      "@@@STEP_LOG_END@json.output (invalid)@@@",
+      "@@@STEP_LOG_LINE@json.output (exception)@No JSON object could be decoded@@@",
+      "@@@STEP_LOG_END@json.output (exception)@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "vpython",
+      "-u",
+      "RECIPE_REPO[depot_tools]/gerrit_client.py",
+      "setlabel",
+      "--host",
+      "https://chromium-review.googlesource.com",
+      "--change",
+      "123",
+      "--json_file",
+      "/path/to/tmp/json",
+      "-l",
+      "commit-queue",
+      "1"
+    ],
+    "env": {
+      "PATH": "<PATH>:RECIPE_REPO[depot_tools]"
+    },
+    "infra_step": true,
+    "name": "gerrit setlabel (2)",
+    "~followup_annotations": [
+      "@@@STEP_LOG_END@json.output (invalid)@@@",
+      "@@@STEP_LOG_LINE@json.output (exception)@No JSON object could be decoded@@@",
+      "@@@STEP_LOG_END@json.output (exception)@@@"
+    ]
+  },
   {
     "cmd": [
       "vpython",

recipes/recipe_modules/gerrit/examples/full.py

@@ -65,6 +65,9 @@ def RunSteps(api):
   api.gerrit.get_change_description(
       host, change=123, patchset=1)
 
+  api.gerrit.set_change_label(host, 123, 'code-review', -1)
+  api.gerrit.set_change_label(host, 123, 'commit-queue', 1)
+
   api.gerrit.abandon_change(host, 123, 'bad roll')
 
   with api.step.defer_results():