Add use-counters for Client-Hints features

Source/core/html/parser/HTMLPreloadScanner.cpp

Index: Source/core/html/parser/HTMLPreloadScanner.cpp
diff --git a/Source/core/html/parser/HTMLPreloadScanner.cpp b/Source/core/html/parser/HTMLPreloadScanner.cpp
index 198db469d2f222fd40d57dc782932981e65af34f..d1e7e7976057d1b121a7547560d8f084cc57e31b 100644
--- a/Source/core/html/parser/HTMLPreloadScanner.cpp
+++ b/Source/core/html/parser/HTMLPreloadScanner.cpp
@@ -521,7 +521,7 @@ void TokenPreloadScanner::scanCommon(const Token& token, const SegmentedString&
                 if (equalIgnoringCase(equivAttributeValue, "content-security-policy"))
                     m_isCSPEnabled = true;
                 else if (equalIgnoringCase(equivAttributeValue, "accept-ch"))
-                    handleAcceptClientHintsHeader(equivAttributeValue, m_clientHintsPreferences);
+                    handleAcceptClientHintsHeader(equivAttributeValue, m_clientHintsPreferences, nullptr);

[Nate Chapin, 2015/06/16 17:10:28]

It's not obvious to me why the ResourceFetcher* parameter is nullptr in some
places but not in others.

                 return;
             }
             const typename Token::Attribute* nameAttribute = token.getAttributeItem(nameAttr);