Remove the html warnings!

tools/dom/dom.json

 {
   "ANGLEInstancedArrays": {
     "members": {
       "VERTEX_ATTRIB_ARRAY_DIVISOR_ANGLE": {
         "support_level": "untriaged"
       },
       "drawArraysInstancedANGLE": {
         "support_level": "untriaged"
       },
       "drawElementsInstancedANGLE": {
@@ skipping 2080 matching lines @@
         "comment": "http://dom.spec.whatwg.org/#dom-documenttype-entities",
         "dart_action": "suppress",
         "support_level": "deprecated"
       },
       "internalSubset": {
         "comment": "http://dom.spec.whatwg.org/#dom-documenttype-internalsubset",
         "dart_action": "suppress",
         "support_level": "deprecated"
       },
       "name": {},
+      "nextElementSibling": {
+        "support_level": "untriaged"
+      },
       "notations": {
         "comment": "http://dom.spec.whatwg.org/#dom-documenttype-notations",
         "dart_action": "suppress",
         "support_level": "deprecated"
       },
+      "previousElementSibling": {
+        "support_level": "untriaged"
+      },
       "publicId": {},
       "remove": {
         "support_level": "nonstandard"
       },
       "systemId": {}
     },
     "support_level": "stable"
   },
   "DynamicsCompressorNode": {
     "comment": "https://dvcs.w3.org/hg/audio/raw-file/tip/webaudio/specification.html#DynamicsCompressorNode",
@@ skipping 118 matching lines @@
         "comment": "http://www.whatwg.org/specs/web-apps/2007-10-26/multipage/section-elements.html#htmlelement",
         "dart_action": "stable",
         "support_level": "nonstandard"
       },
       "innerHTML": {
         "comment": "http://www.whatwg.org/specs/web-apps/2007-10-26/multipage/section-elements.html#htmlelement",
         "dart_action": "stable",
         "support_level": "nonstandard"
       },
       "inputMethodContext": {
+        "comment": "http://www.w3.org/TR/ime-api/#the-inputmethodcontext-property Per the spec is only on HTMLElement.",
+        "dart_action": "suppress",
         "support_level": "untriaged"
       },
       "insertAdjacentElement": {
         "support_level": "untriaged"
       },
       "insertAdjacentHTML": {
         "support_level": "untriaged"
       },
       "insertAdjacentText": {
         "support_level": "untriaged"
@@ skipping 1119 matching lines @@
       "hostname": {},
       "href": {},
       "hreflang": {},
       "name": {
         "comment": "http://www.whatwg.org/specs/web-apps/current-work/multipage/obsolete.html#HTMLAnchorElement-partial",
         "dart_action": "suppress",
         "support_level": "deprecated"
       },
       "origin": {
         "comment": "WebKit only",
-        "dart_action": "suppress",
         "support_level": "nonstandard"
       },
       "password": {
         "support_level": "untriaged"
       },
       "pathname": {},
       "ping": {
         "comment": "http://www.whatwg.org/specs/web-apps/current-work/multipage/text-level-semantics.html#the-a-element",
         "dart_action": "suppress",
         "support_level": "deprecated"
@@ skipping 10687 matching lines @@
       "importStylesheet": {},
       "removeParameter": {},
       "reset": {},
       "setParameter": {},
       "transformToDocument": {},
       "transformToFragment": {}
     },
     "support_level": "nonstandard"
   }
 }