Revert of After detach, there's no document to notify parsing is finished.

third_party/WebKit/Source/core/html/parser/HTMLViewSourceParserTest.cpp

-// Copyright 2016 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "core/html/parser/HTMLViewSourceParser.h"
-
-#include "core/dom/DocumentInit.h"
-#include "core/dom/DocumentParser.h"
-#include "core/html/HTMLViewSourceDocument.h"
-#include "testing/gtest/include/gtest/gtest.h"
-#include "wtf/text/WTFString.h"
-
-namespace blink {
-
-// This is a regression test for https://crbug.com/664915
-TEST(HTMLViewSourceParserTest, DetachThenFinish_ShouldNotCrash) {
-  String mimeType("text/html");
-  HTMLViewSourceDocument* document =
-      HTMLViewSourceDocument::create(DocumentInit(), mimeType);
-  HTMLViewSourceParser* parser =
-      HTMLViewSourceParser::create(*document, mimeType);
-  // A client may detach the parser from the document.
-  parser->detach();
-  // A DocumentWriter may call finish() after detach().
-  static_cast<DocumentParser*>(parser)->finish();
-  // The test passed if finish did not crash.
-}
-
-}  // namespace blink