Use forceClickOnCurrentItem to mean doDefault action rather than performDefaul\

chrome/browser/resources/chromeos/chromevox/chromevox/background/keymaps/next_keymap.json

 {
   "bindings": [
     {
       "command": "previousObject",
       "sequence": {
         "cvoxModifier": true,
         "keys": {
           "keyCode": [37]
         }
       }
@@ skipping 252 matching lines @@
       "command": "jumpToTop",
       "sequence": {
         "cvoxModifier": true,
         "keys": {
           "keyCode": [37],
           "ctrlKey": [true]
         }
       }
     },
     {
-      "command": "performDefaultAction",
+      "command": "forceClickOnCurrentItem",
       "sequence": {
         "cvoxModifier": true,
         "keys": {
           "keyCode": [32]
         }
       }
     },
     {
       "command": "contextMenu",
       "sequence": {
@@ skipping 214 matching lines @@
       "sequence": {
         "cvoxModifier": true,
         "keys": {
           "keyCode": [70],
           "ctrlKey": [true]
         }
       }
     }
   ]
 }