Show deprecation warnings for header values in XHR according to RFC 7230

LayoutTests/http/tests/xmlhttprequest/redirect-cross-origin-tripmine-expected.txt

Index: LayoutTests/http/tests/xmlhttprequest/redirect-cross-origin-tripmine-expected.txt
diff --git a/LayoutTests/http/tests/xmlhttprequest/redirect-cross-origin-tripmine-expected.txt b/LayoutTests/http/tests/xmlhttprequest/redirect-cross-origin-tripmine-expected.txt
index 9c389d527aa152b80286cc2c20b6d8374d50f463..285c12a8b04a965f394e34ccccf36637dea3254f 100644
--- a/LayoutTests/http/tests/xmlhttprequest/redirect-cross-origin-tripmine-expected.txt
+++ b/LayoutTests/http/tests/xmlhttprequest/redirect-cross-origin-tripmine-expected.txt
@@ -1,4 +1,5 @@
 CONSOLE WARNING: Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. For more help, check http://xhr.spec.whatwg.org/.
+CONSOLE WARNING: isValidHTTPHeaderValue() will be deprecated and will be removed in future.
 CONSOLE ERROR: XMLHttpRequest cannot load http://localhost:8000/resources/tripmine.php. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://127.0.0.1:8000' is therefore not allowed access.
 CONSOLE ERROR: XMLHttpRequest cannot load http://localhost:8000/resources/tripmine.php. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://127.0.0.1:8000' is therefore not allowed access.
 CONSOLE ERROR: XMLHttpRequest cannot load http://localhost:8000/resources/tripmine.php. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://127.0.0.1:8000' is therefore not allowed access.