Don't call lower() on KURL protocol/host

third_party/WebKit/Source/platform/weborigin/KnownPorts.cpp

Index: third_party/WebKit/Source/platform/weborigin/KnownPorts.cpp
diff --git a/third_party/WebKit/Source/platform/weborigin/KnownPorts.cpp b/third_party/WebKit/Source/platform/weborigin/KnownPorts.cpp
index 812fc30e30b514a4a417bfda0d8d7f36cfe80fba..2fdb2f4ff729301da51be50e2d8b633ea40deb32 100644
--- a/third_party/WebKit/Source/platform/weborigin/KnownPorts.cpp
+++ b/third_party/WebKit/Source/platform/weborigin/KnownPorts.cpp
@@ -69,7 +69,9 @@ bool isPortAllowedForScheme(const KURL& url) {
   // through non-network schemes that don't go over the network.
   if (!url.hasPort())
     return true;
-  String protocol = url.protocol().isNull() ? "" : url.protocol().lower();
+  String protocol = url.protocol();
+  if (protocol.isNull())
+    protocol = emptyString();
   unsigned short effectivePort = url.port();
   if (!effectivePort)
     effectivePort = defaultPortForProtocol(protocol);