Revert of Add presubmit rule banning relative header includes

PRESUBMIT.py

Index: PRESUBMIT.py
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 8af2e6749d11732536c0351139fa3a258f7bc1b7..4ba36c1e391eb6f7a314e8df636bce7aa1c2cad4 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -2157,43 +2157,6 @@
 https://chromium.googlesource.com/chromium/src/+/master/docs/es6_chromium.md#Arrow-Functions
 """ % "\n".join("  %s:%d\n" % line for line in arrow_lines))]
 
-
-def _CheckForRelativeIncludes(input_api, output_api):
-  from cpp_checker import CppChecker
-
-  bad_files = {}
-  for f in input_api.AffectedFiles(include_deletes=False):
-    if (f.LocalPath().startswith('third_party') and
-      not f.LocalPath().startswith('third_party/WebKit') and
-      not f.LocalPath().startswith('third_party\\WebKit')):
-      continue
-
-    if not CppChecker.IsCppFile(f.LocalPath()):
-      continue
-
-    relative_includes = [line for line_num, line in f.ChangedContents()
-                         if "#include" in line and "../" in line]
-    bad_files[f.LocalPath()] = relative_includes
-
-  if not bad_files:
-    return []
-
-  error_descriptions = []
-  for file_path, bad_lines in bad_files.iteritems():
-    error_description = file_path
-    for line in bad_lines:
-      error_description += '\n    ' + line
-    error_descriptions.append(error_description)
-
-  results = []
-  results.append(output_api.PresubmitError(
-        'You added one or more relative #include paths (including "../").\n'
-        'These shouldn\'t be used because they can be used to include headers\n'
-        'from code that\'s not correctly specified as a dependency in the\n'
-        'relevant BUILD.gn file(s).',
-        error_descriptions))
-
-  return results
 
 def _AndroidSpecificOnUploadChecks(input_api, output_api):
   """Groups checks that target android code."""
@@ -2256,7 +2219,6 @@
   results.extend(_CheckIpcOwners(input_api, output_api))
   results.extend(_CheckUselessForwardDeclarations(input_api, output_api))
   results.extend(_CheckForRiskyJsFeatures(input_api, output_api))
-  results.extend(_CheckForRelativeIncludes(input_api, output_api))
 
   if any('PRESUBMIT.py' == f.LocalPath() for f in input_api.AffectedFiles()):
     results.extend(input_api.canned_checks.RunUnitTestsInDirectory(