Skip the screenshot_sync test properly.

testing/scripts/run_telemetry_benchmark_as_googletest.py

 #!/usr/bin/env python
 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Runs an isolate bundled Telemetry benchmark.
 
 This script attempts to emulate the contract of gtest-style tests
 invoked via recipes. The main contract is that the caller passes the
 argument:
@@ skipping 62 matching lines @@
           failures.append(results['pages'][str(value['page_id'])]['name'])
       valid = bool(rc == 0 or failures)
     except Exception:
       traceback.print_exc()
       valid = False
     finally:
       shutil.rmtree(tempfile_dir)
 
     if not valid and not failures:
       failures = ['(entire test suite)']
+      if rc == 0:
+        rc = 1  # Signal an abnormal exit.
+
     json.dump({
         'valid': valid,
         'failures': failures,
     }, args.isolated_script_test_output)
     return rc
 
   finally:
     xvfb.kill(xvfb_proc)
     xvfb.kill(openbox_proc)
 
 
 # This is not really a "script test" so does not need to manually add
 # any additional compile targets.
 def main_compile_targets(args):
   json.dump([], args.output)
 
 
 if __name__ == '__main__':
   # Conform minimally to the protocol defined by ScriptTest.
   if 'compile_targets' in sys.argv:
     funcs = {
       'run': None,
       'compile_targets': main_compile_targets,
     }
     sys.exit(common.run_script(sys.argv[1:], funcs))
   sys.exit(main())