Add checks for READMEs for each virtual test suite.

Tools/Scripts/webkitpy/layout_tests/lint_test_expectations.py

Index: Tools/Scripts/webkitpy/layout_tests/lint_test_expectations.py
diff --git a/Tools/Scripts/webkitpy/layout_tests/lint_test_expectations.py b/Tools/Scripts/webkitpy/layout_tests/lint_test_expectations.py
index 70998e195b28b338ce8ece36eae156d378fb69d7..70c04f68860521c195fec266e4a1d2eda519f92b 100644
--- a/Tools/Scripts/webkitpy/layout_tests/lint_test_expectations.py
+++ b/Tools/Scripts/webkitpy/layout_tests/lint_test_expectations.py
@@ -46,46 +46,77 @@ EXCEPTIONAL_EXIT_STATUS = 254
 _log = logging.getLogger(__name__)
 
 
-def lint(host, options, logging_stream):
+def lint(host, options):
+    # FIXME: Remove this when we remove the --chromium flag (crbug.com/245504).
+    if options.platform == 'chromium':
+        options.platform = None
+
+    ports_to_lint = [host.port_factory.get(name) for name in host.port_factory.all_port_names(options.platform)]
+    files_linted = set()
+    lint_failed = False
+
+    for port_to_lint in ports_to_lint:
+        expectations_dict = port_to_lint.expectations_dict()
+
+        for expectations_file in expectations_dict.keys():
+            if expectations_file in files_linted:
+                continue
+
+            try:
+                test_expectations.TestExpectations(port_to_lint,
+                    expectations_dict={expectations_file: expectations_dict[expectations_file]},
+                    is_lint_mode=True)
+            except test_expectations.ParseError as e:
+                lint_failed = True
+                _log.error('')
+                for warning in e.warnings:
+                    _log.error(warning)
+                _log.error('')
+            files_linted.add(expectations_file)
+    return lint_failed
+
+
+def check_virtual_test_suites(host, options):
+    port = host.port_factory.get(options=options)
+    fs = host.filesystem
+    layout_tests_dir = port.layout_tests_dir()
+    virtual_suites = port.virtual_test_suites()
+
+    check_failed = False
+    for suite in virtual_suites:
+        comps = [layout_tests_dir] + suite.name.split('/') + ['README.txt']
+        path_to_readme = fs.join(*comps)
+        if not fs.exists(path_to_readme):
+            _log.error('LayoutTests/%s/README.txt is missing (each virtual suite must have one).' % suite.name)
+            check_failed = True
+    if check_failed:
+        _log.error('')
+    return check_failed
+
+
+def set_up_logging(logging_stream):
     logger = logging.getLogger()
     logger.setLevel(logging.INFO)
     handler = logging.StreamHandler(logging_stream)
     logger.addHandler(handler)
+    return (logger, handler)
 
+
+def tear_down_logging(logger, handler):
+    logger.removeHandler(handler)
+
+
+def run_checks(host, options, logging_stream):
+    logger, handler = set_up_logging(logging_stream)
     try:
-        # FIXME: Remove this when we remove the --chromium flag (crbug.com/245504).
-        if options.platform == 'chromium':
-            options.platform = None
-
-        ports_to_lint = [host.port_factory.get(name) for name in host.port_factory.all_port_names(options.platform)]
-        files_linted = set()
-        lint_failed = False
-
-        for port_to_lint in ports_to_lint:
-            expectations_dict = port_to_lint.expectations_dict()
-
-            for expectations_file in expectations_dict.keys():
-                if expectations_file in files_linted:
-                    continue
-
-                try:
-                    test_expectations.TestExpectations(port_to_lint,
-                        expectations_dict={expectations_file: expectations_dict[expectations_file]},
-                        is_lint_mode=True)
-                except test_expectations.ParseError as e:
-                    lint_failed = True
-                    _log.error('')
-                    for warning in e.warnings:
-                        _log.error(warning)
-                    _log.error('')
-                files_linted.add(expectations_file)
-
-        if lint_failed:
+        lint_failed = lint(host, options)
+        check_failed = check_virtual_test_suites(host, options)
+        if lint_failed or check_failed:
             _log.error('Lint failed.')
-            return -1
-
-        _log.info('Lint succeeded.')
-        return 0
+            return 1
+        else:
+            _log.info('Lint succeeded.')
+            return 0
     finally:
         logger.removeHandler(handler)
 
@@ -104,7 +135,7 @@ def main(argv, _, stderr):
         host = Host()
 
     try:
-        exit_status = lint(host, options, stderr)
+        exit_status = run_checks(host, options, stderr)
     except KeyboardInterrupt:
         exit_status = INTERRUPTED_EXIT_STATUS
     except Exception as e: