Remove support for multipart/x-mixed-replace

LayoutTests/http/tests/multipart/policy-ignore-crash.php

Index: LayoutTests/http/tests/multipart/policy-ignore-crash.php
diff --git a/LayoutTests/http/tests/multipart/policy-ignore-crash.php b/LayoutTests/http/tests/multipart/policy-ignore-crash.php
deleted file mode 100644
index 09b59494fecfe242e7c8ff94b700ea0bc9c677e7..0000000000000000000000000000000000000000
--- a/LayoutTests/http/tests/multipart/policy-ignore-crash.php
+++ /dev/null
@@ -1,30 +0,0 @@
-<?php
-header('Content-type: multipart/x-mixed-replace;boundary=asdf');
-?>--asdf
-Content-type: text/html
-
-<p>This test passes if it does not crash.</p>
-<script>
-if (window.testRunner)
-    testRunner.dumpAsText();
-</script>
-
-<?php
-# Add some padding because CFNetwork merges small multipart segments together.
-echo str_pad('', 5000);
-
-ob_flush();
-flush();
-?>
---asdf
-Content-type: text/rtf
-
-This chunk has an unsupported text mime type, which can cause the policy
-for this load to be ignored. This causes the request to be canceled.
-
-<?php
-# Add some padding because CFNetwork merges small multipart segments together.
-echo str_pad('', 5000);
-?>
-
---asdf--