remove getPreCompressedContentFormats from HttpContent

Signed-off-by: Lachlan Roberts <lachlan@webtide.com>

jetty-core/jetty-http/src/main/java/org/eclipse/jetty/http/HttpContent.java

@@ -17,7 +17,6 @@ import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.time.Instant;
 import java.util.Map;
-import java.util.Set;
 
 import org.eclipse.jetty.http.MimeTypes.Type;
 import org.eclipse.jetty.util.resource.Resource;
@@ -64,12 +63,6 @@ public interface HttpContent
 
     Map<CompressedContentFormat, ? extends HttpContent> getPrecompressedContents();
 
-    default Set<CompressedContentFormat> getPreCompressedContentFormats()
-    {
-        Map<CompressedContentFormat, ? extends HttpContent> precompressedContents = getPrecompressedContents();
-        return (precompressedContents == null) ? Set.of() : precompressedContents.keySet();
-    }
-
     ByteBuffer getBuffer();
 
     void release();

jetty-core/jetty-http/src/main/java/org/eclipse/jetty/http/PrecompressedHttpContent.java

@@ -16,7 +16,6 @@ package org.eclipse.jetty.http;
 import java.nio.ByteBuffer;
 import java.time.Instant;
 import java.util.Map;
-import java.util.Set;
 
 import org.eclipse.jetty.http.MimeTypes.Type;
 import org.eclipse.jetty.util.resource.Resource;
@@ -144,12 +143,6 @@ public class PrecompressedHttpContent implements HttpContent
         return null;
     }
 
-    @Override
-    public Set<CompressedContentFormat> getPreCompressedContentFormats()
-    {
-        return Set.of();
-    }
-
     @Override
     public ByteBuffer getBuffer()
     {

jetty-core/jetty-server/src/main/java/org/eclipse/jetty/server/ResourceService.java

@@ -204,7 +204,7 @@ public class ResourceService
             if (passConditionalHeaders(request, response, content, callback))
                 return;
 
-            if (!content.getPreCompressedContentFormats().isEmpty() || content instanceof PrecompressedHttpContent)
+            if (!_precompressedFormats.isEmpty())
                 response.getHeaders().put(HttpHeader.VARY, HttpHeader.ACCEPT_ENCODING.asString());
 
             HttpField contentEncoding = content.getContentEncoding();