Split SVGImage-related cases into separate UseCounter histograms

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 20 matching lines @@
 #include "core/css/parser/CSSParserMode.h"
 #include "wtf/BitVector.h"
 #include "wtf/Noncopyable.h"
 #include "wtf/text/WTFString.h"
 #include <v8.h>
 
 namespace blink {
 
 class CSSStyleSheet;
 class Document;
+class EnumerationHistogram;
 class ExecutionContext;
 class Frame;
 class LocalFrame;
 class StyleSheetContents;
 
 // UseCounter is used for counting the number of times features of
 // Blink are used on real web pages and help us know commonly
 // features are used and thus when it's safe to remove or change them.
 //
 // The Chromium Content layer controls what is done with this data.
 // For instance, in Google Chrome, these counts are submitted
 // anonymously through the Histogram recording system in Chrome
 // for users who opt-in to "Usage Statistics" submission
 // during their install of Google Chrome:
 // http://www.google.com/chrome/intl/en/privacy.html
 
 class CORE_EXPORT UseCounter {
     DISALLOW_NEW();
     WTF_MAKE_NONCOPYABLE(UseCounter);
 public:
-    UseCounter();
+    enum Context {
+        DefaultContext,
+        // Counters for SVGImages (lifetime independent from other pages).
+        SVGImageContext
+    };
+
+    UseCounter(Context = DefaultContext);
 
     enum Feature {
         // Do not change assigned numbers of existing items: add new features
         // to the end of the list.
         OBSOLETE_PageDestruction = 0,
         PrefixedIndexedDB = 3,
         WorkerStart = 4,
         SharedWorkerStart = 5,
         UnprefixedIndexedDB = 9,
         OpenWebDatabase = 10,
@@ skipping 1257 matching lines @@
     static int mapCSSPropertyIdToCSSSampleIdForHistogram(CSSPropertyID);
 
     void muteForInspector();
     void unmuteForInspector();
 
     void recordMeasurement(Feature);
     void updateMeasurements();
 
     bool hasRecordedMeasurement(Feature) const;
 
-protected:
+private:
+    EnumerationHistogram& featuresHistogram() const;
+    EnumerationHistogram& cssHistogram() const;
+
+    unsigned m_muteCount;
+    Context m_context;
+
+    // Track what features/properties have been reported to the (non-legacy) histograms.
+    BitVector m_featuresRecorded;
+    BitVector m_CSSRecorded;
+
     // Encapsulates the work to preserve the old "FeatureObserver" histogram with original semantics
     // TODO(rbyers): remove this - http://crbug.com/597963
     class LegacyCounter {
     public:
         LegacyCounter();
         ~LegacyCounter();
         void countFeature(Feature);
         void countCSS(CSSPropertyID);
         void updateMeasurements();
     private:
         // Tracks what features/properties need to be reported to the legacy histograms.
         BitVector m_featureBits;
         BitVector m_CSSBits;
     } m_legacyCounter;
-
-    unsigned m_muteCount;
-
-    // Track what features/properties have been reported to the (non-legacy) histograms.
-    BitVector m_featuresRecorded;
-    BitVector m_CSSRecorded;
 };
 
 } // namespace blink
 
 #endif // UseCounter_h