Presentation API: add UMA.

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 795 matching lines @@
         AudioParamExponentialRampToValueAtTime = 911,
         AudioParamSetTargetAtTime = 912,
         AudioParamSetValueCurveAtTime = 913,
         AudioParamCancelScheduledValues = 914,
         V8Permissions_Request_Method = 915,
         LinkRelSubresource = 916,
         LinkRelPrefetch = 917,
         LinkRelPrerender = 918,
         LinkRelNext = 919,
         PrefixedPerformanceResourceTimingBufferFull = 920,
+        PresentationDefaultRequest = 921,
+        PresentationAvailabilityChangeEventListener = 922,
+        PresentationRequestConstructor = 923,
+        PresentationRequestStart = 924,
+        PresentationRequestJoin = 925,
+        PresentationRequestGetAvailability = 926,
+        PresentationRequestSessionConnectEventListener = 927,
+        PresentationSessionClose = 928,
+        PresentationSessionSend = 929,
+        PresentationSessionStateChangeEventListener = 930,
+        PresentationSessionMessageEventListener = 931,
 
         // 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.
     };
 
     // "count" sets the bit for this feature to 1. Repeated calls are ignored.
     static void count(const Frame*, Feature);
@@ skipping 83 matching lines @@
 
     bool hasRecordedMeasurement(Feature feature) const { return m_countBits.hasRecordedMeasurement(feature); }
 
     CountBits m_countBits;
     BitVector m_CSSFeatureBits;
 };
 
 } // namespace blink
 
 #endif // UseCounter_h