Check that external references are registered in the serializer.

PRESUBMIT.py

 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 24 matching lines @@
 
 
 def _V8PresubmitChecks(input_api, output_api):
   """Runs the V8 presubmit checks."""
   import sys
   sys.path.append(input_api.os_path.join(
         input_api.PresubmitLocalPath(), 'tools'))
   from presubmit import CppLintProcessor
   from presubmit import SourceProcessor
   from presubmit import CheckGeneratedRuntimeTests
+  from presubmit import CheckExternalReferenceRegistration
 
   results = []
   if not CppLintProcessor().Run(input_api.PresubmitLocalPath()):
     results.append(output_api.PresubmitError("C++ lint check failed"))
   if not SourceProcessor().Run(input_api.PresubmitLocalPath()):
     results.append(output_api.PresubmitError(
         "Copyright header, trailing whitespaces and two empty lines " \
         "between declarations check failed"))
   if not CheckGeneratedRuntimeTests(input_api.PresubmitLocalPath()):
     results.append(output_api.PresubmitError(
         "Generated runtime tests check failed"))
+  if not CheckExternalReferenceRegistration(input_api.PresubmitLocalPath()):
+    results.append(output_api.PresubmitError(
+        "External references registration check failed"))
   return results
 
 
 def _CheckUnwantedDependencies(input_api, output_api):
   """Runs checkdeps on #include statements added in this
   change. Breaking - rules is an error, breaking ! rules is a
   warning.
   """
   # We need to wait until we have an input_api object and use this
   # roundabout construct to import checkdeps because this file is
@@ skipping 106 matching lines @@
       'v8_linux_nosnap_dbg': set(['defaulttests']),
       'v8_linux64_rel': set(['defaulttests']),
       'v8_linux_arm_dbg': set(['defaulttests']),
       'v8_linux_arm64_rel': set(['defaulttests']),
       'v8_linux_layout_dbg': set(['defaulttests']),
       'v8_mac_rel': set(['defaulttests']),
       'v8_win_rel': set(['defaulttests']),
       'v8_win64_rel': set(['defaulttests']),
     },
   }