Add use-counters for Client-Hints features

Source/core/fetch/ClientHintsPreferences.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/fetch/ClientHintsPreferences.h"
 
+#include "core/fetch/ResourceFetcher.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/network/HTTPParsers.h"
 
 namespace blink {
 
-void handleAcceptClientHintsHeader(const String& headerValue, ClientHintsPreferences& preferences)
+void handleAcceptClientHintsHeader(const String& headerValue, ClientHintsPreferences& preferences, ResourceFetcher* fetcher)
 {
     if (!RuntimeEnabledFeatures::clientHintsEnabled() || headerValue.isEmpty())
         return;
     CommaDelimitedHeaderSet acceptCH;
     parseCommaDelimitedHeader(headerValue, acceptCH);
-    if (acceptCH.contains("dpr"))
+    if (acceptCH.contains("dpr")) {
+        if (fetcher)
+            fetcher->context().countClientHintsDPR();
         preferences.setShouldSendDPR(true);
+    }
 
-    if (acceptCH.contains("width"))
+    if (acceptCH.contains("width")) {
+        if (fetcher)
+            fetcher->context().countClientHintsResourceWidth();
         preferences.setShouldSendResourceWidth(true);
+    }
 
-    if (acceptCH.contains("viewport-width"))
+    if (acceptCH.contains("viewport-width")) {
+        if (fetcher)
+            fetcher->context().countClientHintsViewportWidth();
         preferences.setShouldSendViewportWidth(true);
+    }
 }
 
 }