Changed the css feature name trace string to avoid collisions

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

 /*
  * 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 1212 matching lines @@
   DCHECK(isCSSPropertyIDWithName(property));
 
   if (!isUseCounterEnabledForMode(cssParserMode) || m_muteCount)
     return;
 
   if (!m_CSSRecorded.quickGet(property)) {
     // Note that HTTPArchive tooling looks specifically for this event - see
     // https://github.com/HTTPArchive/httparchive/issues/59
     int sampleId = mapCSSPropertyIdToCSSSampleIdForHistogram(property);
     TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("blink.feature_usage"),
-                 "CSSFeatureFirstUsed", "feature", sampleId);
+                 "CSSFirstUsed", "feature", sampleId);
     cssHistogram().count(sampleId);
     m_CSSRecorded.quickSet(property);
   }
   m_legacyCounter.countCSS(property);
 }
 
 void UseCounter::count(Feature feature) {
   DCHECK(Deprecation::deprecationMessage(feature).isEmpty());
   recordMeasurement(feature);
 }
@@ skipping 103 matching lines @@
     }
   }
 
   if (needsPagesMeasuredUpdate)
     cssPropertiesHistogram.count(totalPagesMeasuredCSSSampleId());
 
   m_CSSBits.clearAll();
 }
 
 }  // namespace blink