Revert of "Implement the inert attribute"

third_party/WebKit/LayoutTests/external/wpt/html/dom/elements/elements-in-the-dom/historical.html

Index: third_party/WebKit/LayoutTests/external/wpt/html/dom/elements/elements-in-the-dom/historical.html
diff --git a/third_party/WebKit/LayoutTests/external/wpt/html/dom/elements/elements-in-the-dom/historical.html b/third_party/WebKit/LayoutTests/external/wpt/html/dom/elements/elements-in-the-dom/historical.html
index 078ce29cc029bd51554d839ff4dc792a78cc8371..469ff08ca5b6a3ead9a936a35d45922e554e24d3 100644
--- a/third_party/WebKit/LayoutTests/external/wpt/html/dom/elements/elements-in-the-dom/historical.html
+++ b/third_party/WebKit/LayoutTests/external/wpt/html/dom/elements/elements-in-the-dom/historical.html
@@ -15,6 +15,8 @@
   "commandTriggers",
   // https://github.com/whatwg/html/pull/2402
   "dropzone",
+  // https://github.com/whatwg/html/commit/5ddfc78b1f82e86cc202d72ccc752a0e15f1e4ad
+  "inert",
 ].forEach(function(member) {
   test(function() {
     assert_false(member in document.body);