headless-chromium: fix access permission for some installed files

Installed files are owned by slapsoft but some folders has rx permission
for group which cause permission denied when slapuserXX try to access
them.

component/headless-chromium/buildout.cfg

@@ -111,6 +111,11 @@ environment =
   AR="${:llvm-toolchain}/llvm-ar"
   NM="${:llvm-toolchain}/llvm-nm"
 
+# Fix permission for group, slapuserXX should be able to access subfolders
+# in headless-chromium location.
+post-install =
+  find ${:fake-location} -type d -exec chmod g+xr {} \;
+
 # Expose devtools frontend location.
 devtools-frontend = ${:fake-location}/gen/third_party/devtools-frontend/src/front_end