[wptrunner] Add testdriver flag to non-testharness manifest items

This will let wptrunner gracefully skip testdriver tests if the executor
doesn't support them.

tools/manifest/item.py

@@ -166,7 +166,7 @@ def pac(self) -> Optional[Text]:
         return self._extras.get("pac")
 
     @property
-    def testdriver(self) -> Optional[Text]:
+    def testdriver(self) -> Optional[bool]:
         return self._extras.get("testdriver")
 
     @property
@@ -240,6 +240,10 @@ def fuzzy(self) -> Fuzzy:
             rv[key] = v
         return rv
 
+    @property
+    def testdriver(self) -> Optional[bool]:
+        return self._extras.get("testdriver")
+
     def to_json(self) -> Tuple[Optional[Text], List[Tuple[Text, Text]], Dict[Text, Any]]:  # type: ignore
         rel_url = None if self._url == self.path else self._url
         rv: Tuple[Optional[Text], List[Tuple[Text, Text]], Dict[Text, Any]] = (rel_url, self.references, {})
@@ -252,6 +256,8 @@ def to_json(self) -> Tuple[Optional[Text], List[Tuple[Text, Text]], Dict[Text, A
             extras["dpi"] = self.dpi
         if self.fuzzy:
             extras["fuzzy"] = list(self.fuzzy.items())
+        if self.testdriver:
+            extras["testdriver"] = self.testdriver
         return rv
 
     @classmethod
@@ -315,6 +321,16 @@ class CrashTest(URLManifestItem):
     def timeout(self) -> Optional[Text]:
         return None
 
+    @property
+    def testdriver(self) -> Optional[bool]:
+        return self._extras.get("testdriver")
+
+    def to_json(self):  # type: ignore
+        rel_url, extras = super().to_json()
+        if self.testdriver:
+            extras["testdriver"] = self.testdriver
+        return rel_url, extras
+
 
 class WebDriverSpecTest(URLManifestItem):
     __slots__ = ()

tools/manifest/sourcefile.py

@@ -927,7 +927,8 @@ def manifest_items(self) -> Tuple[Text, List[ManifestItem]]:
                     self.tests_root,
                     self.rel_path,
                     self.url_base,
-                    self.rel_url
+                    self.rel_url,
+                    testdriver=self.has_testdriver,
                 )]
 
         elif self.name_is_print_reftest:
@@ -946,6 +947,7 @@ def manifest_items(self) -> Tuple[Text, List[ManifestItem]]:
                     viewport_size=self.viewport_size,
                     fuzzy=self.fuzzy,
                     page_ranges=self.page_ranges,
+                    testdriver=self.has_testdriver,
                 )]
 
         elif self.name_is_multi_global:
@@ -1046,7 +1048,8 @@ def manifest_items(self) -> Tuple[Text, List[ManifestItem]]:
                     timeout=self.timeout,
                     viewport_size=self.viewport_size,
                     dpi=self.dpi,
-                    fuzzy=self.fuzzy
+                    fuzzy=self.fuzzy,
+                    testdriver=self.has_testdriver,
                 ))
 
         elif self.content_is_css_visual and not self.name_is_reference:

tools/manifest/tests/test_manifest.py

@@ -335,3 +335,29 @@ def test_manifest_spec_to_json():
             ]}},
         }
     }
+
+
+@pytest.mark.parametrize("testdriver,expected_extra", [
+    (True, {"testdriver": True}),
+    # Don't bloat the manifest with the `testdriver=False` default.
+    (False, {}),
+])
+def test_dump_testdriver(testdriver, expected_extra):
+    m = manifest.Manifest("")
+    source_file = SourceFileWithTest("a" + os.path.sep + "b", "0"*40, item.RefTest,
+                                     testdriver=testdriver)
+
+    tree, sourcefile_mock = tree_and_sourcefile_mocks([(source_file, None, True)])
+    with mock.patch("tools.manifest.manifest.SourceFile", side_effect=sourcefile_mock):
+        assert m.update(tree) is True
+
+    assert m.to_json() == {
+        'version': 8,
+        'url_base': '/',
+        'items': {
+            'reftest': {'a': {'b': [
+                '0000000000000000000000000000000000000000',
+                (None, [], expected_extra)
+            ]}},
+        }
+    }