Make clear SupportsRequestPriority() also implies connection sharing.

net/http/http_server_properties.h

Index: net/http/http_server_properties.h
diff --git a/net/http/http_server_properties.h b/net/http/http_server_properties.h
index 4f680b784cc75a8d0a5d15dfe04110ec710bcfbb..f0ffcc5d7770d09e7b924ea23bd3be5193242b78 100644
--- a/net/http/http_server_properties.h
+++ b/net/http/http_server_properties.h
@@ -234,6 +234,9 @@ class NET_EXPORT HttpServerProperties {
 
   // Returns true if |server| supports a network protocol which honors
   // request prioritization.
+  // Note that this also implies that the server supports request
+  // multiplexing, since priorities imply a relationship between
+  // multiple requests.
   virtual bool SupportsRequestPriority(const url::SchemeHostPort& server) = 0;
 
   // Returns the value set by SetSupportsSpdy(). If not set, returns false.