Add use-counters for Client-Hints features

Source/core/fetch/ClientHintsPreferences.cpp

Index: Source/core/fetch/ClientHintsPreferences.cpp
diff --git a/Source/core/fetch/ClientHintsPreferences.cpp b/Source/core/fetch/ClientHintsPreferences.cpp
index 1f4c25e0e4f9103d64fc2b3b023b902629513ed6..1d4874f9e16458da8c96b8c4fd312eec50805e54 100644
--- a/Source/core/fetch/ClientHintsPreferences.cpp
+++ b/Source/core/fetch/ClientHintsPreferences.cpp
@@ -5,25 +5,35 @@
 #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().count(FetchContext::ClientHintsDPR);
         preferences.setShouldSendDPR(true);
+    }
 
-    if (acceptCH.contains("width"))
+    if (acceptCH.contains("width")) {
+        if (fetcher)
+            fetcher->context().count(FetchContext::ClientHintsResourceWidth);
         preferences.setShouldSendResourceWidth(true);
+    }
 
-    if (acceptCH.contains("viewport-width"))
+    if (acceptCH.contains("viewport-width")) {
+        if (fetcher)
+            fetcher->context().count(FetchContext::ClientHintsViewportWidth);
         preferences.setShouldSendViewportWidth(true);
+    }
 }
 
 }