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 1579 matching lines @@
     kCredentialManagerIdName = 1985,
     kCredentialManagerPasswordName = 1986,
     kCredentialManagerAdditionalData = 1987,
     kCredentialManagerCustomFetch = 1988,
     kNetInfoRtt = 1989,
     kNetInfoDownlink = 1990,
     kShapeDetection_BarcodeDetectorConstructor = 1991,
     kShapeDetection_FaceDetectorConstructor = 1992,
     kShapeDetection_TextDetectorConstructor = 1993,
     kCredentialManagerCredentialRequestOptionsOnlyUnmediated = 1994,
-    // TODO(aboxhall): Reuse value 1995 when
-    // https://codereview.chromium.org/2088453002 is relanded.
+    kInertAttribute = 1995,
     kPluginInstanceAccessFromIsolatedWorld = 1996,
     kPluginInstanceAccessFromMainWorld = 1997,
     kRequestFullscreenForDialogElement = 1998,
     kRequestFullscreenForDialogElementInTopLayer = 1999,
     kShowModalForElementInFullscreenStack = 2000,
     kThreeValuedPositionBackground = 2001,
     kThreeValuedPositionBasicShape = 2002,
     kThreeValuedPositionGradient = 2003,
     kThreeValuedPositionObjectPosition = 2004,
     kThreeValuedPositionPerspectiveOrigin = 2005,
@@ skipping 107 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