add chardet.universaldetector (#3734)

third_party/2and3/chardet/__init__.pyi

@@ -0,0 +1,4 @@
+from typing import Any
+from .universaldetector import UniversalDetector as UniversalDetector
+
+def __getattr__(name: str) -> Any: ...  # incomplete

third_party/2and3/chardet/universaldetector.pyi

@@ -0,0 +1,31 @@
+import sys
+from typing import Dict, Union, AnyStr, Pattern, Optional
+from typing_extensions import TypedDict
+from logging import Logger
+
+class _FinalResultType(TypedDict):
+    encoding: str
+    confidence: float
+    language: str
+
+class _IntermediateResultType(TypedDict):
+    encoding: Optional[str]
+    confidence: float
+    language: Optional[str]
+
+class UniversalDetector(object):
+    MINIMUM_THRESHOLD: float
+    HIGH_BYTE_DETECTOR: Pattern[bytes]
+    ESC_DETECTOR: Pattern[bytes]
+    WIN_BYTE_DETECTOR: Pattern[bytes]
+    ISO_WIN_MAP: Dict[str, str]
+
+    result: _IntermediateResultType
+    done: bool
+    lang_filter: int
+    logger: Logger
+
+    def __init__(self, lang_filter: int) -> None: ...
+    def reset(self) -> None: ...
+    def feed(self, byte_str: bytes) -> None: ...
+    def close(self) -> _FinalResultType: ...