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

Source/WebCore/page/Page.cpp

Index: Source/WebCore/page/Page.cpp
diff --git a/Source/WebCore/page/Page.cpp b/Source/WebCore/page/Page.cpp
index 14f19c9e68b02d42bdbbfba8ad5177d404b13fee..ab5a94e00e70d96559426b91f2a09e98d3f2c7d6 100644
--- a/Source/WebCore/page/Page.cpp
+++ b/Source/WebCore/page/Page.cpp
@@ -1211,7 +1211,7 @@ void Page::reportMemoryUsage(MemoryObjectInfo* memoryObjectInfo) const
     info.addMember(m_mainFrame, "mainFrame");
     info.addMember(m_pluginData, "pluginData");
     info.addMember(m_theme, "theme");
-    info.addMember(m_featureObserver, "featureObserver");
+    info.addMember(m_UseCounter, "UseCounter");
     info.addMember(m_groupName, "groupName");
     info.addMember(m_pagination, "pagination");
     info.addMember(m_userStyleSheet, "userStyleSheet");