Teach the background parser to ignore certain elements inside '<select>'.

third_party/WebKit/Source/core/html/parser/HTMLTreeBuilderSimulator.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 43 matching lines @@
   const State& state() const { return m_namespaceStack; }
   void setState(const State& state) { m_namespaceStack = state; }
 
   SimulatedToken simulate(const CompactHTMLToken&, HTMLTokenizer*);
 
  private:
   bool inForeignContent() const { return m_namespaceStack.back() != HTML; }
 
   HTMLParserOptions m_options;
   State m_namespaceStack;
+  bool m_inSelectInsertionMode;
 };
 
 }  // namespace blink
 
 #endif