Move 'autofocus' IDL attribute to HTMLOrSVGElement

crrev.com/697042 changed the autofocus behavior, and this CL just changes
the IDL attribute.

Note: We need to add 'autofocus' to svg_attribute_names.json5
because generated code for 'Reflect' needs svg_names::kAutofocusAttr.
html_names::kAutofocusAttr and svg_names::kAutofocusAttr have
an identical value.

I2IS: https://groups.google.com/a/chromium.org/d/msg/blink-dev/g8MP8KUf96w/360rLewrDwAJ

Bug: 995679
Change-Id: I4c7a1ad72d14c4e1e54d8455935b1255805fb384
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1808617
Commit-Queue: Kent Tamura <[email protected]>
Reviewed-by: Keishi Hattori <[email protected]>
Cr-Commit-Position: refs/heads/master@{#697087}

html/dom/elements-forms.js

@@ -27,7 +27,6 @@ var formElements = {
     accept: "string",
     alt: "string",
     autocomplete: {type: "string", customGetter: true},
-    autofocus: "boolean",
     defaultChecked: {type: "boolean", domAttrName: "checked"},
     dirName: "string",
     disabled: "boolean",
@@ -65,7 +64,6 @@ var formElements = {
     useMap: "string",
   },
   button: {
-    autofocus: "boolean",
     disabled: "boolean",
     // "formAction" has magic hard-coded in reflection.js
     formAction: "url",
@@ -79,7 +77,6 @@ var formElements = {
   },
   select: {
     autocomplete: {type: "string", customGetter: true},
-    autofocus: "boolean",
     disabled: "boolean",
     multiple: "boolean",
     name: "string",
@@ -99,7 +96,6 @@ var formElements = {
   },
   textarea: {
     autocomplete: {type: "string", customGetter: true},
-    autofocus: "boolean",
     cols: {type: "limited unsigned long with fallback", defaultVal: 20},
     dirName: "string",
     disabled: "boolean",

html/dom/reflection.js

@@ -900,6 +900,7 @@ for (var element in elements) {
     ReflectionTests.reflects({type: "enum", keywords: ["ltr", "rtl", "auto"]}, "dir", element);
     ReflectionTests.reflects("string", "className", element, "class");
     ReflectionTests.reflects("tokenlist", "classList", element, "class");
+    ReflectionTests.reflects("boolean", "autofocus", element);
     ReflectionTests.reflects("boolean", "hidden", element);
     ReflectionTests.reflects("string", "accessKey", element);
     // Don't try to test the defaultVal -- it should be either 0 or -1, but the