Regenerate MANIFEST.json when WPT tests are run

third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/base.py

Index: third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/base.py
diff --git a/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/base.py b/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/base.py
index f52c30fa86fc82e98aa037dcb95976e23ca74996..6e9bef12902631abe88bc0144d1611c2ef4d3321 100644
--- a/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/base.py
+++ b/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/base.py
@@ -738,8 +738,22 @@ class Port(object):
             tests.append(file_path)
         return tests
 
+    def _generate_manifest(self, dest_path):

[qyearsley, 2017/01/19 23:56:19]

I usually like to put helper methods under the methods that use them, because in
general this leads to a sequence of methods where higher-level bigger-picture
methods come first.

Here, since dest_path is only ever going to be the wpt directory, you could
remove that argument and have a variable
  wpt_path = self._webkit_finder.path_from_webkit_base('LayoutTests',
'external', 'wpt')

Then you could remove the logic for "css" below.

+        manifest_path = self._webkit_finder.path_from_webkit_base(
+            'Tools', 'Scripts', 'webkitpy', 'thirdparty', 'wpt', 'wpt', 'manifest')
+
+        if 'css' in dest_path:
+            # Do nothing for csswg-test.
+            return
+        _log.info('Generating MANIFEST.json')
+        self._executive.run_command([manifest_path, '--work', '--tests-root', dest_path])
+
     @memoized
     def _wpt_manifest(self):
+        # Regenerate manifest

[qyearsley, 2017/01/19 23:56:19]

Not sure if this comment is necessary, since the method name generate_manifest
should make this clear enough.

+        dest_path = self._webkit_finder.path_from_webkit_base('LayoutTests', 'external', 'wpt')
+        self._generate_manifest(dest_path)
+
         path = self._filesystem.join(self.layout_tests_dir(), 'external', 'wpt', 'MANIFEST.json')
         return json.loads(self._filesystem.read_text_file(path))