Create a top-level "third_party" directory

This directory now contains third_party software that is vendored into
the Servo source tree. The idea is that it would eventually hold
webrender and other crates from mozilla-central as well with a standard
patch management approach for each.

components/script/dom/bindings/codegen/run.py

@@ -6,14 +6,18 @@ import os
 import sys
 import json
 
+SCRIPT_PATH = os.path.abspath(os.path.dirname(__file__))
+SERVO_ROOT = os.path.abspath(os.path.join(SCRIPT_PATH, "..", "..", "..", "..", ".."))
+
 
 def main():
     os.chdir(os.path.join(os.path.dirname(__file__)))
-    sys.path[0:0] = ["./parser", "./ply"]
+    sys.path.insert(0, os.path.join(SERVO_ROOT, "third_party", "WebIDL"))
+    sys.path.insert(0, os.path.join(SERVO_ROOT, "third_party", "ply"))
 
     css_properties_json, out_dir = sys.argv[1:]
-    doc_servo = "../../../../../target/doc/servo"
+    doc_servo = os.path.join(SERVO_ROOT, "target", "doc", "servo")
-    webidls_dir = "../../webidls"
+    webidls_dir = os.path.join(SCRIPT_PATH, "..", "..", "webidls")
     config_file = "Bindings.conf"
 
     import WebIDL

python/servo/testing_commands.py

@@ -327,8 +327,8 @@ class MachCommands(CommandBase):
 
         if all or tests:
             print("Running WebIDL tests...")
-            test_file_dir = path.abspath(path.join(PROJECT_TOPLEVEL_PATH, "components", "script",
+
-                                                   "dom", "bindings", "codegen", "parser"))
+            test_file_dir = path.abspath(path.join(PROJECT_TOPLEVEL_PATH, "third_party", "WebIDL"))
             # For the `import WebIDL` in runtests.py
             sys.path.insert(0, test_file_dir)
             run_file = path.abspath(path.join(test_file_dir, "runtests.py"))

servo-tidy.toml

@@ -140,12 +140,11 @@ directories = [
   "./tests/wpt/mozilla/tests/mozilla/referrer-policy",
   "./tests/wpt/mozilla/tests/webgl",
   "./python/tidy/tests",
-  "./components/script/dom/bindings/codegen/parser",
-  "./components/script/dom/bindings/codegen/ply",
   "./python/_virtualenv*",
   "./python/mach",
   # Generated and upstream code combined with our own. Could use cleanup
   "./target",
+  "./third_party",
 ]
 
 # Directories that are checked for correct file extension