DevTools: roll closure compiler to 20161201.

third_party/WebKit/Source/devtools/scripts/compile_frontend.py

 #!/usr/bin/env python
 # Copyright (c) 2012 Google Inc. 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
@@ skipping 212 matching lines @@
 java_exec = find_java()
 
 closure_compiler_jar = to_platform_path(path.join(scripts_path, 'closure', 'compiler.jar'))
 closure_runner_jar = to_platform_path(path.join(scripts_path, 'closure', 'closure_runner', 'closure_runner.jar'))
 jsdoc_validator_jar = to_platform_path(path.join(scripts_path, 'jsdoc_validator', 'jsdoc_validator.jar'))
 
 modules_dir = tempfile.mkdtemp()
 common_closure_args = [
     '--summary_detail_level', '3',
     '--jscomp_error', 'visibility',
+    '--jscomp_warning', 'missingOverride',
     '--compilation_level', 'SIMPLE_OPTIMIZATIONS',
     '--warning_level', 'VERBOSE',
     '--language_in=ES6_STRICT',
     '--language_out=ES5_STRICT',
     '--extra_annotation_name', 'suppressReceiverCheck',
     '--extra_annotation_name', 'suppressGlobalPropertiesCheck',
+    '--checks-only',
     '--module_output_path_prefix', to_platform_path_exact(modules_dir + path.sep)
 ]
 
 worker_modules_by_name = {}
 dependents_by_module_name = {}
 
 for module_name in descriptors.application:
     module = descriptors.modules[module_name]
     if descriptors.application[module_name].get('type', None) == 'worker':
         worker_modules_by_name[module_name] = module
@@ skipping 199 matching lines @@
 print 'devtools_compatibility.js compilation output:%s' % os.linesep, devtools_js_compile_out
 errors_found |= has_errors(devtools_js_compile_out)
 
 os.remove(compiler_args_file.name)
 os.remove(protocol_externs_file)
 shutil.rmtree(modules_dir, True)
 
 if errors_found:
     print 'ERRORS DETECTED'
     sys.exit(1)