Check kMaxDescriptorsPerMessage in test_packaged_app.cc

ppapi/tests/DEPS

 # ppapi/tests should not be dependent on other parts of chromium; it should stay
 # browser-neutral as much as possible.
 include_rules = [
   "-base",
   "-build",
   "-ipc",
   "-uncode",
   "-testing",
   "-ppapi",
   "+ppapi/c",
   "+ppapi/cpp",
   "+ppapi/lib",
   "+ppapi/tests",
   "+ppapi/utility",
 
   # Test to confirm whether PPB_Audio_Shared works properly in NaCl needs to
   # call nacl_irt_ppapihook internally to emulate some erroneous situation.
   "+native_client/src/untrusted/irt/irt.h",
   "+ppapi/native_client/src/untrusted/irt_stub/thread_creator.h",
 ]
 # checkdeps.py shouldn't check include paths for files in clang, which aren't
 # part of the chrome build.
 skip_child_includes = [
    "clang",
 ]
+specific_include_rules = {
+  # extensions/packaged_app/test_packaged_app.cc uses kMaxDescriptorsPerMessage
+  # defined in ipc/ipc_message_attachment_set.h.
+  "test_packaged_app\.cc": [
+    "+ipc/ipc_message_attachment_set.h",
+  ]
+}