Reduce string copies in GURL creation

content/renderer/pepper/pepper_plugin_instance_impl.cc

Index: content/renderer/pepper/pepper_plugin_instance_impl.cc
diff --git a/content/renderer/pepper/pepper_plugin_instance_impl.cc b/content/renderer/pepper/pepper_plugin_instance_impl.cc
index 172c3b7e1c1b740cfe74c72d0cf1dc991719d198..1b0c8dbb2cd7bc1b75aa6319c7ea7cdbcb4cfbc7 100644
--- a/content/renderer/pepper/pepper_plugin_instance_impl.cc
+++ b/content/renderer/pepper/pepper_plugin_instance_impl.cc
@@ -25,6 +25,7 @@
 #include "cc/layers/texture_layer.h"
 #include "content/common/content_constants_internal.h"
 #include "content/common/frame_messages.h"
+#include "content/public/child/url_conversion.h"
 #include "content/public/common/content_constants.h"
 #include "content/public/renderer/content_renderer_client.h"
 #include "content/renderer/pepper/content_decryptor_delegate.h"
@@ -2863,7 +2864,7 @@ PP_Var PepperPluginInstanceImpl::GetPluginReferrerURL(
   WebString referer = request.httpHeaderField("Referer");
   if (referer.isEmpty())
     return PP_MakeUndefined();
-  return ppapi::PPB_URLUtil_Shared::GenerateURLReturn(GURL(referer),
+  return ppapi::PPB_URLUtil_Shared::GenerateURLReturn(WebStringToGURL(referer),
                                                       components);
 }