servo: Merge #7103 - Use one Python virtual environment for all mach commands (from frewsxcv:python-venv); r=metajack

*See individual commits for more information*

Source-Repo: https://github.com/servo/servo
Source-Revision: c315404db80c92a695531b0aa4bcf61c125a3bff

servo/python/tidy.py

@@ -19,11 +19,6 @@ from licenseck import licenses
 filetypes_to_check = [".rs", ".rc", ".cpp", ".c", ".h", ".py", ".toml", ".webidl"]
 reftest_directories = ["tests/ref"]
 reftest_filetype = ".list"
-python_dependencies = [
-    "./python/dependencies/flake8-2.4.1-py2.py3-none-any.whl",
-    "./python/dependencies/pep8-1.5.7-py2.py3-none-any.whl",
-    "./python/dependencies/pyflakes-0.9.0-py2.py3-none-any.whl",
-]
 
 ignored_files = [
     # Upstream
@@ -36,6 +31,7 @@ ignored_files = [
     "python/toml/*",
     "components/script/dom/bindings/codegen/parser/*",
     "components/script/dom/bindings/codegen/ply/*",
+    "python/_virtualenv/*",
 
     # Generated and upstream code combined with our own. Could use cleanup
     "target/*",
@@ -240,7 +236,6 @@ def check_spec(file_name, contents):
 
 
 def collect_errors_for_files(files_to_check, checking_functions):
-    base_path = "components/script/dom/"
     for file_name in files_to_check:
         with open(file_name, "r") as fp:
             contents = fp.read()
@@ -273,8 +268,6 @@ def get_reftest_names(line):
 
 
 def scan():
-    sys.path += python_dependencies
-
     all_files = collect_file_names()
     files_to_check = filter(should_check, all_files)