[Reland] Introduce telemetry.web_components and a simple component-based Results object

tools/telemetry/PRESUBMIT.py

 # Copyright (c) 2012 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.
 import os
 import sys
 
 PYLINT_BLACKLIST = []
 PYLINT_DISABLED_WARNINGS = ['R0923', 'R0201', 'E1101']
 
 def _CommonChecks(input_api, output_api):
   results = []
 
   # TODO(nduca): This should call update_docs.IsUpdateDocsNeeded().
   # Disabled due to crbug.com/255326.
   if False:
     update_docs_path = os.path.join(
       input_api.PresubmitLocalPath(), 'update_docs')
     assert os.path.exists(update_docs_path)
     results.append(output_api.PresubmitError(
       'Docs are stale. Please run:\n' +
       '$ %s' % os.path.abspath(update_docs_path)))
 
+  # Importing telemetry.web_components actually brings tvcm into the path.
+  import telemetry.web_components # pylint: disable=W0612
+  from tvcm import presubmit_checker
+  checker = presubmit_checker.PresubmitChecker(input_api, output_api)
+  results += checker.RunChecks()
+
   results.extend(input_api.canned_checks.RunPylint(
         input_api, output_api,
         black_list=PYLINT_BLACKLIST,
         disabled_warnings=PYLINT_DISABLED_WARNINGS))
   return results
 
 def GetPathsToPrepend(input_api):
   return [input_api.PresubmitLocalPath()]
 
 def RunWithPrependedPath(prepended_path, fn, *args):
@@ skipping 11 matching lines @@
     results.extend(_CommonChecks(input_api, output_api))
     return results
   return RunWithPrependedPath(GetPathsToPrepend(input_api), go)
 
 def CheckChangeOnCommit(input_api, output_api):
   def go():
     results = []
     results.extend(_CommonChecks(input_api, output_api))
     return results
   return RunWithPrependedPath(GetPathsToPrepend(input_api), go)