Remove the HTMLMediaElementControllerNotNull use counter

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 256 matching lines @@
         FormNameAccessForPastNamesMap = 247,
         FormAssociationByParser = 248,
         SVGSVGElementInDocument = 250,
         SVGDocumentRootElement = 251,
         DocumentCreateEventOptionalArgument = 252,
         MediaErrorEncrypted = 253,
         EventSourceURL = 254,
         WebSocketURL = 255,
         WorkerSubjectToCSP = 257,
         WorkerAllowedByChildBlockedByScript = 258,
-        HTMLMediaElementControllerNotNull = 259,
         DeprecatedWebKitGradient = 260,
         DeprecatedWebKitLinearGradient = 261,
         DeprecatedWebKitRepeatingLinearGradient = 262,
         DeprecatedWebKitRadialGradient = 263,
         DeprecatedWebKitRepeatingRadialGradient = 264,
         PrefixedImageSmoothingEnabled = 267,
         UnprefixedImageSmoothingEnabled = 268,
         PromiseConstructor = 270,
         PromiseCast = 271,
         PromiseReject = 272,
@@ skipping 137 matching lines @@
 
     void updateMeasurements();
 
     OwnPtr<BitVector> m_countBits;
     BitVector m_CSSFeatureBits;
 };
 
 } // namespace WebCore
 
 #endif // UseCounter_h