Add detailed use counters for document.registerElement use.

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 1473 matching lines @@
     VRPoseLinearVelocity = 1863,
     VRPoseLinearAcceleration = 1864,
     VRPoseAngularVelocity = 1865,
     VRPoseAngularAcceleration = 1866,
     CSSOverflowPaged = 1867,
     ChildSrcAllowedWorkerThatScriptSrcBlocked = 1868,
     HTMLTableElementPresentationAttributeBackground = 1869,
     V8Navigator_GetInstalledRelatedApps_Method = 1870,
     NamedAccessOnWindow_ChildBrowsingContext = 1871,
     NamedAccessOnWindow_ChildBrowsingContext_CrossOriginNameMismatch = 1872,
+    V0CustomElementsRegisterHTMLCustomTag = 1873,
+    V0CustomElementsRegisterHTMLTypeExtension = 1874,
+    V0CustomElementsRegisterSVGElement = 1875,
+    V0CustomElementsRegisterEmbedderElement = 1876,
+    V0CustomElementsCreateCustomTagElement = 1877,
+    V0CustomElementsCreateTypeExtensionElement = 1878,
+    V0CustomElementsConstruct = 1879,
 
     // 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.
     NumberOfFeatures,  // 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
@@ skipping 99 matching lines @@
     // Tracks what features/properties need to be reported to the legacy
     // histograms.
     BitVector m_featureBits;
     BitVector m_CSSBits;
   } m_legacyCounter;
 };
 
 }  // namespace blink
 
 #endif  // UseCounter_h