Add step generator protocol, remove annotated_checkout, remove script.

scripts/slave/recipes_test/toolkit.basic.expected

Index: scripts/slave/recipes_test/toolkit.basic.expected
diff --git a/scripts/slave/recipes_test/toolkit.basic.expected b/scripts/slave/recipes_test/toolkit.basic.expected
index 5e2cecb2a25afda625f10d7ab46fa14446039187..4062d026a8640da910a10d491d187e978ab460f4 100644
--- a/scripts/slave/recipes_test/toolkit.basic.expected
+++ b/scripts/slave/recipes_test/toolkit.basic.expected
@@ -1 +1,10 @@
-"[BUILD_ROOT]/slave/fake_slave/build/toolkit/buildbot/gen_steps.py"
+[
+  {"cmd": ["[BUILD_ROOT]/scripts/slave/git_setup.py", "--path", "[SLAVE_BUILD_ROOT]/toolkit", "--url", "https://github.com/toolkitchen/toolkit.git"], "name": "git setup", "seed_steps": ["git setup", "git fetch", "git update-ref", "git clean", "git checkout", "git submodule"]},
+  {"cmd": ["git", "--work-tree", "[SLAVE_BUILD_ROOT]/toolkit", "--git-dir", "[SLAVE_BUILD_ROOT]/toolkit/.git", "fetch", "origin", "--recurse-submodules"], "name": "git fetch"},
+  {"cmd": ["git", "--work-tree", "[SLAVE_BUILD_ROOT]/toolkit", "--git-dir", "[SLAVE_BUILD_ROOT]/toolkit/.git", "update-ref", "refs/heads/master", "origin/master"], "name": "git update-ref"},
+  {"cmd": ["git", "--work-tree", "[SLAVE_BUILD_ROOT]/toolkit", "--git-dir", "[SLAVE_BUILD_ROOT]/toolkit/.git", "clean", "-f", "-d", "-X"], "name": "git clean"},
+  {"cmd": ["git", "--work-tree", "[SLAVE_BUILD_ROOT]/toolkit", "--git-dir", "[SLAVE_BUILD_ROOT]/toolkit/.git", "checkout", "-f", "master"], "name": "git checkout"},
+  {"cmd": ["git", "--work-tree", "[SLAVE_BUILD_ROOT]/toolkit", "--git-dir", "[SLAVE_BUILD_ROOT]/toolkit/.git", "submodule", "update", "--init", "--recursive"], "name": "git submodule"},
+  {"cmd": ["[SLAVE_BUILD_ROOT]/toolkit/buildbot/gen_steps.py", "--factory-properties", "{\"recipe\": \"toolkit\"}", "--build-properties", "{\"blamelist\": [\"cool_dev1337@chromium.org\"], \"patchset\": 1, \"rietveld\": \"https://chromiumcodereview.appspot.com\", \"issue\": 12853011, \"repository\": \"https://github.com/toolkitchen/toolkit\"}", "--output-json", "/path/to/tmp/json"], "cwd": "[SLAVE_BUILD_ROOT]/toolkit", "name": "gen step(gen_steps.py)"},
+  {"cmd": ["bogus.py", "--arg"], "name": "bogus", "seed_steps": ["bogus"]}
+]