Remove support for the obsolete <isindex> tag.

LayoutTests/http/tests/misc/isindex-formdata.html

Index: LayoutTests/http/tests/misc/isindex-formdata.html
diff --git a/LayoutTests/http/tests/misc/isindex-formdata.html b/LayoutTests/http/tests/misc/isindex-formdata.html
deleted file mode 100644
index 56af83c53f27cdd39ef91a375279ae317168360a..0000000000000000000000000000000000000000
--- a/LayoutTests/http/tests/misc/isindex-formdata.html
+++ /dev/null
@@ -1,42 +0,0 @@
-<script>
-function test()
-{
-    if (!location.search.length) {
-        if (window.testRunner) {
-            testRunner.dumpAsText();
-            testRunner.waitUntilDone();
-        }
-
-        if (!document.getElementById("isindex")) {
-            log("Could not find isindex element");
-            if (window.testRunner)
-                testRunner.notifyDone();
-            return;
-        }
-        document.getElementById("isindex").value = "This is a test";
-        document.forms[0].submit();
-    } else {
-        var expected = "?This+is+a+test";
-        if (location.search != expected)
-            log("FAIL: Expected \"" + expected + "\" but got \"" + location.search + "\"");
-        else
-            log("PASS");
-
-        if (window.testRunner)
-            testRunner.notifyDone();
-    }
-}
-
-function log(msg)
-{
-    document.getElementById("log").appendChild(document.createTextNode(msg + "\n"));
-}
-
-window.onload = test;
-
-</script>
-<p>This page tests that we correctly put the value of an <tt>&lt;isindex&gt;</tt> element into the form data.</p>
-<form method="GET" action="isindex-formdata.html">
-    <isindex id="isindex"></isindex>
-</form>
-<pre id="log"></pre>