Make Document.charset an alias of characterSet, as per spec

third_party/WebKit/Source/core/frame/UseCounter.h

 /*
  * Copyright (C) 2012 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 124 matching lines @@
         SubFrameBeforeUnloadRegistered = 97,
         SubFrameBeforeUnloadFired = 98,
         ConsoleMarkTimeline = 102,
         ElementGetAttributeNode = 107,
         ElementSetAttributeNode = 108,
         ElementRemoveAttributeNode = 109,
         ElementGetAttributeNodeNS = 110,
         DocumentCreateAttribute = 111,
         DocumentCreateAttributeNS = 112,
         DocumentCreateCDATASection = 113, // Removed from DOM4.
-        DocumentInputEncoding = 114,
         DocumentXMLEncoding = 115, // Removed from DOM4.
         DocumentXMLStandalone = 116, // Removed from DOM4.
         DocumentXMLVersion = 117, // Removed from DOM4.
         NodeIsSameNode = 118, // Removed from DOM4.
         NavigatorProductSub = 123,
         NavigatorVendor = 124,
         NavigatorVendorSub = 125,
         FileError = 126,
-        DocumentCharset = 127, // Documented as IE extensions = 0, from KHTML days.
         PrefixedAnimationEndEvent = 128,
         UnprefixedAnimationEndEvent = 129,
         PrefixedAndUnprefixedAnimationEndEvent = 130,
         PrefixedAnimationStartEvent = 131,
         UnprefixedAnimationStartEvent = 132,
         PrefixedAndUnprefixedAnimationStartEvent = 133,
         PrefixedAnimationIterationEvent = 134,
         UnprefixedAnimationIterationEvent = 135,
         PrefixedAndUnprefixedAnimationIterationEvent = 136,
         EventReturnValue = 137, // Legacy IE extension.
@@ skipping 773 matching lines @@
 
     bool hasRecordedMeasurement(Feature feature) const { return m_countBits.hasRecordedMeasurement(feature); }
 
     CountBits m_countBits;
     BitVector m_CSSFeatureBits;
 };
 
 } // namespace blink
 
 #endif // UseCounter_h