Implement the inert attribute

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 1576 matching lines @@
     kFontShapingNotDefGlyphObserved = 1973,
     kPostMessageOutgoingWouldBeBlockedByConnectSrc = 1974,
     kPostMessageIncomingWouldBeBlockedByConnectSrc = 1975,
     kPaymentRequestNetworkNameInSupportedMethods = 1976,
     kCrossOriginPropertyAccess = 1977,
     kCrossOriginPropertyAccessFromOpener = 1978,
     kCredentialManagerCreate = 1979,
     kWebDatabaseCreateDropFTS3Table = 1980,
     kFieldEditInSecureContext = 1981,
     kFieldEditInNonSecureContext = 1982,
+    kInertAttribute = 1983,
 
     // Add new features immediately above this line. Don't change assigned
     // numbers of any item, and don't reuse removed slots.
     // Also, run update_use_counter_feature_enum.py in
     // chromium/src/tools/metrics/histograms/ to update the UMA mapping.
     kNumberOfFeatures,  // This enum value must be last.
   };
 
   // An interface to observe UseCounter changes. Note that this is never
   // notified when the counter is disabled by |m_muteCount| or when |m_context|
@@ skipping 97 matching lines @@
     // Tracks what features/properties need to be reported to the legacy
     // histograms.
     BitVector feature_bits_;
     BitVector css_bits_;
   } legacy_counter_;
 };
 
 }  // namespace blink
 
 #endif  // UseCounter_h