Rename FeatureObserver to UseCounter to make clear that all it stores are usage counts.

Source/WebCore/page/FeatureObserver.h

Index: Source/WebCore/page/FeatureObserver.h
diff --git a/Source/WebCore/page/FeatureObserver.h b/Source/WebCore/page/FeatureObserver.h
deleted file mode 100644
index 55b4092157a24a33dc0823b6c464811941a334f3..0000000000000000000000000000000000000000
--- a/Source/WebCore/page/FeatureObserver.h
+++ /dev/null
@@ -1,139 +0,0 @@
-/*
- * 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
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY GOOGLE INC. ``AS IS'' AND ANY
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
- * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
- * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#ifndef FeatureObserver_h
-#define FeatureObserver_h
-
-#include <wtf/BitVector.h>
-#include <wtf/Noncopyable.h>
-#include <wtf/OwnPtr.h>
-#include <wtf/PassOwnPtr.h>
-
-namespace WebCore {
-
-class DOMWindow;
-class Document;
-
-class FeatureObserver {
-    WTF_MAKE_NONCOPYABLE(FeatureObserver);
-public:
-    FeatureObserver();
-    ~FeatureObserver();
-
-    enum Feature {
-        PageDestruction,
-        LegacyNotifications,
-        MultipartMainResource,
-        PrefixedIndexedDB,
-        WorkerStart,
-        SharedWorkerStart,
-        LegacyWebAudio,
-        WebAudioStart,
-        PrefixedContentSecurityPolicy,
-        UnprefixedIndexedDB,
-        OpenWebDatabase,
-        LegacyHTMLNotifications,
-        LegacyTextNotifications,
-        UnprefixedRequestAnimationFrame,
-        PrefixedRequestAnimationFrame,
-        ContentSecurityPolicy,
-        ContentSecurityPolicyReportOnly,
-        PrefixedContentSecurityPolicyReportOnly,
-        PrefixedTransitionEndEvent,
-        UnprefixedTransitionEndEvent,
-        PrefixedAndUnprefixedTransitionEndEvent,
-        AutoFocusAttribute,
-        AutoSaveAttribute,
-        DataListElement,
-        FormAttribute,
-        IncrementalAttribute,
-        InputTypeColor,
-        InputTypeDate,
-        InputTypeDateTime,
-        InputTypeDateTimeFallback,
-        InputTypeDateTimeLocal,
-        InputTypeEmail,
-        InputTypeMonth,
-        InputTypeNumber,
-        InputTypeRange,
-        InputTypeSearch,
-        InputTypeTel,
-        InputTypeTime,
-        InputTypeURL,
-        InputTypeWeek,
-        InputTypeWeekFallback,
-        ListAttribute,
-        MaxAttribute,
-        MinAttribute,
-        PatternAttribute,
-        PlaceholderAttribute,
-        PrecisionAttribute,
-        PrefixedDirectoryAttribute,
-        PrefixedSpeechAttribute,
-        RequiredAttribute,
-        ResultsAttribute,
-        StepAttribute,
-        PageVisits,
-        HTMLMarqueeElement,
-        CSSOverflowMarquee,
-        Reflection,
-        CursorVisibility,
-        StorageInfo,
-        XFrameOptions,
-        XFrameOptionsSameOrigin,
-        XFrameOptionsSameOriginWithBadAncestorChain,
-        DeprecatedFlexboxWebContent,
-        DeprecatedFlexboxChrome,
-        DeprecatedFlexboxChromeExtension,
-        // Add new features above this line. Don't change assigned numbers of each items.
-        NumberOfFeatures, // This enum value must be last.
-    };
-
-    static void observe(Document*, Feature);
-    static void observe(DOMWindow*, Feature);
-    void didCommitLoad();
-
-    const BitVector* accumulatedFeatureBits() const { return m_featureBits.get(); }
-
-private:
-    void didObserve(Feature feature)
-    {
-        ASSERT(feature != PageDestruction); // PageDestruction is reserved as a scaling factor.
-        ASSERT(feature < NumberOfFeatures);
-        if (!m_featureBits) {
-            m_featureBits = adoptPtr(new BitVector(NumberOfFeatures));
-            m_featureBits->clearAll();
-        }
-        m_featureBits->quickSet(feature);
-    }
-
-    void updateMeasurements();
-
-    OwnPtr<BitVector> m_featureBits;
-};
-
-} // namespace WebCore
-    
-#endif // FeatureObserver_h