Add tests for fullscreenchange and fullscreenerror event timing

third_party/WebKit/LayoutTests/imported/wpt/MANIFEST.json

 {
   "items": {
     "manual": [],
     "reftest": [],
     "stub": [],
     "testharness": [],
     "wdspec": []
   },
   "local_changes": {
     "deleted": [],
     "deleted_reftests": {},
     "items": {
       "manual": {
         "fullscreen/api/document-exit-fullscreen-manual.html": [
           {
             "path": "fullscreen/api/document-exit-fullscreen-manual.html",
             "url": "/fullscreen/api/document-exit-fullscreen-manual.html"
           }
         ],
+        "fullscreen/api/document-exit-fullscreen-timing-manual.html": [
+          {
+            "path": "fullscreen/api/document-exit-fullscreen-timing-manual.html",
+            "url": "/fullscreen/api/document-exit-fullscreen-timing-manual.html"
+          }
+        ],
         "fullscreen/api/document-fullscreen-element-manual.html": [
           {
             "path": "fullscreen/api/document-fullscreen-element-manual.html",
             "url": "/fullscreen/api/document-fullscreen-element-manual.html"
           }
         ],
         "fullscreen/api/document-onfullscreenchange-manual.html": [
           {
             "path": "fullscreen/api/document-onfullscreenchange-manual.html",
             "url": "/fullscreen/api/document-onfullscreenchange-manual.html"
@@ skipping 52 matching lines @@
             "path": "fullscreen/api/element-request-fullscreen-svg-rect-manual.html",
             "url": "/fullscreen/api/element-request-fullscreen-svg-rect-manual.html"
           }
         ],
         "fullscreen/api/element-request-fullscreen-svg-svg-manual.html": [
           {
             "path": "fullscreen/api/element-request-fullscreen-svg-svg-manual.html",
             "url": "/fullscreen/api/element-request-fullscreen-svg-svg-manual.html"
           }
         ],
+        "fullscreen/api/element-request-fullscreen-timing-manual.html": [
+          {
+            "path": "fullscreen/api/element-request-fullscreen-timing-manual.html",
+            "url": "/fullscreen/api/element-request-fullscreen-timing-manual.html"
+          }
+        ],
         "fullscreen/api/element-request-fullscreen-top-manual.html": [
           {
             "path": "fullscreen/api/element-request-fullscreen-top-manual.html",
             "url": "/fullscreen/api/element-request-fullscreen-top-manual.html"
           }
         ],
         "fullscreen/model/remove-child-manual.html": [
           {
             "path": "fullscreen/model/remove-child-manual.html",
             "url": "/fullscreen/model/remove-child-manual.html"
@@ skipping 20104 matching lines @@
           "url": "/svg/linking/reftests/href-use-element.html"
         }
       ]
     }
   },
   "reftest_nodes": {},
   "rev": null,
   "url_base": "/",
   "version": 3
 }