remoteexec: Add comment about hard-coded paths.

BUG=chromium:1256966
TEST=run_tests

Change-Id: I6182635b28a0974da57c6401f11a190c08fa6990
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/3328030
Reviewed-by: Alex Klein <saklein@chromium.org>
Tested-by: Joanna Wang <jojwang@chromium.org>
Auto-Submit: Joanna Wang <jojwang@chromium.org>
Commit-Queue: Joanna Wang <jojwang@chromium.org>
diff --git a/api/controller/sysroot.py b/api/controller/sysroot.py
index a182eb0..dd33896 100644
--- a/api/controller/sysroot.py
+++ b/api/controller/sysroot.py
@@ -241,8 +241,8 @@
   compile_source = (
       input_proto.flags.compile_source or input_proto.flags.toolchain_changed)
 
-  # TODO(crbug.com/1256966): Check if input_proto.remoteexec_config exists.
-  use_remoteexec = False
+  use_remoteexec = bool(input_proto.remoteexec_config.reproxy_cfg_file and
+                        input_proto.remoteexec_config.reclient_dir)
 
   # Testing if Goma will support unknown compilers now.
   use_goma = input_proto.flags.use_goma and not use_remoteexec