toolchain_util: AFDO generation artifact cleanup.

BUG=chromium:1019868
TEST=led jobs
TEST=unit tests

Change-Id: I6003bbe1f3e90ef4fa72368bd2d08ce971081daa
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/2153546
Commit-Queue: LaMont Jones <lamontjones@chromium.org>
Tested-by: LaMont Jones <lamontjones@chromium.org>
Reviewed-by: David Burger <dburger@chromium.org>
Reviewed-by: Tiancong Wang <tcwang@google.com>
diff --git a/api/controller/toolchain.py b/api/controller/toolchain.py
index dd9e1d4..aef942e 100644
--- a/api/controller/toolchain.py
+++ b/api/controller/toolchain.py
@@ -175,8 +175,7 @@
 # TODO(crbug/1031213): When @faux is expanded to have more than success/failure,
 # this should be changed.
 @faux.all_empty
-@validate.require('chroot.path', 'sysroot.path', 'sysroot.build_target.name',
-                  'output_dir', 'artifact_types')
+@validate.require('chroot.path', 'output_dir', 'artifact_types')
 @validate.exists('output_dir')
 @validate.validation_complete
 def BundleArtifacts(input_proto, output_proto, _config):
@@ -185,9 +184,10 @@
   The handlers (from _TOOLCHAIN_ARTIFACT_HANDLERS above) are called with:
       artifact_name (str): name of the artifact type
       chroot (chroot_lib.Chroot): chroot
-      sysroot_path (str): sysroot path inside the chroot (e.g., /build/atlas)
+      sysroot_path (str): sysroot path inside the chroot (e.g., /build/atlas),
+          or None.
       chrome_root (str): path to chrome root. (e.g., /b/s/w/ir/k/chrome)
-      build_target_name (str): name of the build target (e.g., atlas)
+      build_target_name (str): name of the build target (e.g., atlas), or None.
       output_dir (str): absolute path where artifacts are being bundled.
         (e.g., /b/s/w/ir/k/recipe_cleanup/artifactssptfMU)
       profile_info ({(str) name: (str) value}) Dictionary containing profile