Add fuzzer for HTMLPreloadScanner

third_party/WebKit/Source/core/html/parser/HTMLPreloadScanner.h

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  * Copyright (C) 2010 Google Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 52 matching lines @@
         return wrapUnique(new CachedDocumentParameters(document));
     }
 
     bool doHtmlPreloadScanning;
     bool doDocumentWritePreloadScanning;
     Length defaultViewportMinWidth;
     bool viewportMetaZeroValuesQuirk;
     bool viewportMetaEnabled;
     ReferrerPolicy referrerPolicy;
 
+protected:
+    // For testing.
+    CachedDocumentParameters() {}

[kouhei (in TOK), 2016/08/22 05:48:28]

public:
static std::unique_ptr<CachedDocumentParameters> create() { return
wrapUnique(new CachedDocumentParameters); }

private:
CachedDocumentParameters() = default;
?

[Charlie Harrison, 2016/08/23 01:32:28]

I'm inclined to keep a protected constructor here because fuzzers are optimized
for stack allocations over heap allocations.

Given your other comment, though, it may be better for style to just do this.

[kouhei (in TOK), 2016/08/23 02:29:41]

I'm fine either way. Not a blocker.
However we seem to be heap alloc-ing this anyway in Fuzzer.cpp:
"CachedDocumentParametersForFuzzing* documentParameters = new
CachedDocumentParametersForFuzzing(fuzzedData);"

+
 private:
     explicit CachedDocumentParameters(Document*);
 };
 
 class TokenPreloadScanner {
     WTF_MAKE_NONCOPYABLE(TokenPreloadScanner); USING_FAST_MALLOC(TokenPreloadScanner);
 public:
     TokenPreloadScanner(const KURL& documentURL, std::unique_ptr<CachedDocumentParameters>, const MediaValuesCached::MediaValuesCachedData&);
     ~TokenPreloadScanner();
 
@@ skipping 86 matching lines @@
 
     TokenPreloadScanner m_scanner;
     SegmentedString m_source;
     HTMLToken m_token;
     std::unique_ptr<HTMLTokenizer> m_tokenizer;
 };
 
 } // namespace blink
 
 #endif