Make it possible to modify background HTML parser token limits.

Source/core/html/parser/BackgroundHTMLParser.h

 /*
  * Copyright (C) 2013 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 30 matching lines @@
 namespace blink {
 
 class HTMLDocumentParser;
 class XSSAuditor;
 class WebScheduler;
 
 class BackgroundHTMLParser {
     WTF_MAKE_FAST_ALLOCATED(BackgroundHTMLParser);
 public:
     struct Configuration {
+        Configuration();
         HTMLParserOptions options;
         WeakPtr<HTMLDocumentParser> parser;
         OwnPtr<XSSAuditor> xssAuditor;
         OwnPtr<TokenPreloadScanner> preloadScanner;
         OwnPtr<TextResourceDecoder> decoder;
+        // outstandingTokenLimit must be greater than or equal to
+        // pendingTokenLimit
+        size_t outstandingTokenLimit;
+        size_t pendingTokenLimit;
     };
 
     static void start(PassRefPtr<WeakReference<BackgroundHTMLParser>>, PassOwnPtr<Configuration>, WebScheduler*);
 
     struct Checkpoint {
         WeakPtr<HTMLDocumentParser> parser;
         OwnPtr<HTMLToken> token;
         OwnPtr<HTMLTokenizer> tokenizer;
         HTMLTreeBuilderSimulator::State treeBuilderState;
         HTMLInputCheckpoint inputCheckpoint;
@@ skipping 23 matching lines @@
     void sendTokensToMainThread();
     void updateDocument(const String& decodedData);
 
     WeakPtrFactory<BackgroundHTMLParser> m_weakFactory;
     BackgroundHTMLInputStream m_input;
     HTMLSourceTracker m_sourceTracker;
     OwnPtr<HTMLToken> m_token;
     OwnPtr<HTMLTokenizer> m_tokenizer;
     HTMLTreeBuilderSimulator m_treeBuilderSimulator;
     HTMLParserOptions m_options;
+    const size_t m_outstandingTokenLimit;
     WeakPtr<HTMLDocumentParser> m_parser;
 
     OwnPtr<CompactHTMLTokenStream> m_pendingTokens;
+    const size_t m_pendingTokenLimit;
     PreloadRequestStream m_pendingPreloads;
     XSSInfoStream m_pendingXSSInfos;
 
     OwnPtr<XSSAuditor> m_xssAuditor;
     OwnPtr<TokenPreloadScanner> m_preloadScanner;
     OwnPtr<TextResourceDecoder> m_decoder;
     DocumentEncodingData m_lastSeenEncodingData;
     WebScheduler* m_scheduler; // NOT OWNED, scheduler will outlive BackgroundHTMLParser
 
     bool m_startingScript;
 };
 
 }
 
 #endif