Blink web tests: add --no-expectations option for running arbitrary testcases.

https://chromium-review.googlesource.com/c/chromium/src/+/1906472 has broken the
ability to run arbitrary testcases without any expectations. This CL introduces
an explicit option --no-expectations that disables expectation parsing and test
results post-processing. This mode is useful for generating code coverage
reports, as it may work with any arbitrary testcases (passed via --test-list=)
and also should be running faster than the default mode, though likely not
significantly faster, hence I did not measure that aspect.

Bug: 957581
Change-Id: I3c91cb55ba0cad73fa6b39d386c1b37949332ef4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1974699Reviewed-by: Quinten Yearsley <qyearsley@chromium.org>
Commit-Queue: Max Moroz <mmoroz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#726190}

third_party/blink/tools/blinkpy/web_tests/controllers/manager.py

@@ -112,6 +112,7 @@ class Manager(object):
             test_names.sort()
             random.Random(self._options.seed).shuffle(test_names)
 
+        if not self._options.no_expectations:
             self._printer.write_update('Parsing expectations ...')
             self._expectations = test_expectations.TestExpectations(self._port, test_names)
 
@@ -158,6 +159,9 @@ class Manager(object):
             self._stop_servers()
             self._clean_up_run()
 
+        if self._options.no_expectations:
+            return test_run_results.RunDetails(0, [], [], initial_results, all_retry_results)
+
         # Some crash logs can take a long time to be written out so look
         # for new logs after the test run finishes.
         self._printer.write_update('Looking for new crash logs ...')
@@ -302,6 +306,9 @@ class Manager(object):
         return self._is_http_test(test_file) or self._is_perf_test(test_file)
 
     def _test_is_slow(self, test_file):
+        if not self._expectations:
+            return False
+
         expectations = self._expectations.model().get_expectations(test_file)
         return (test_expectations.SLOW in expectations or
                 self._port.is_slow_wpt_test(test_file))

third_party/blink/tools/blinkpy/web_tests/controllers/single_test_runner.py

@@ -45,6 +45,7 @@ def run_single_test(port, options, results_directory, worker_name, driver, test_
     runner = SingleTestRunner(port, options, results_directory, worker_name, driver, test_input)
     try:
         test_result = runner.run()
+        if not options.no_expectations:
             test_result.create_artifacts()
         return test_result
     except DeviceFailure as error:

third_party/blink/tools/blinkpy/web_tests/controllers/web_test_finder.py

@@ -162,6 +162,10 @@ class WebTestFinder(object):
             return line
 
     def skip_tests(self, paths, all_tests_list, expectations, http_tests):
+        if self._options.no_expectations:
+            # do not skip anything.
+            return []
+
         all_tests = set(all_tests_list)
 
         tests_to_skip = expectations.get_tests_with_result_type(test_expectations.SKIP)

third_party/blink/tools/blinkpy/web_tests/controllers/web_test_runner.py

@@ -92,6 +92,7 @@ class WebTestRunner(object):
         self._printer.num_completed = 0
 
         if retry_attempt < 1:
+            if self._expectations:
                 self._printer.print_expected(test_run_results, self._expectations.get_tests_with_result_type)
 
         for test_name in set(tests_to_skip):
@@ -191,6 +192,9 @@ class WebTestRunner(object):
                 test_run_results.unexpected_crashes, test_run_results.unexpected_timeouts))
 
     def _update_summary_with_result(self, test_run_results, result):
+        if not self._expectations:
+            return
+
         expected = self._expectations.matches_an_expected_result(result.test_name, result.type)
         expectation_string = self._expectations.get_expectations_string(result.test_name)
         actual_string = self._expectations.expectation_to_string(result.type)

third_party/blink/tools/blinkpy/web_tests/run_web_tests.py

@@ -177,6 +177,12 @@ def parse_args(args):
                 '--ignore-default-expectations',
                 action='store_true',
                 help=('Do not use the default set of TestExpectations files.')),
+            optparse.make_option(
+                '--no-expectations',
+                action='store_true',
+                help=('Do not use TestExpectations, only run the tests without '
+                      'reporting any results. Useful for generating code '
+                      'coverage reports.')),
             optparse.make_option(
                 '--additional-platform-directory',
                 action='append',