[Switch Access] Remove work around for browser tabs

Also ensures that non-browser tabs are treated as web elements, not
browser tabs.

Unblocks crbug.com/1131689

AX-Relnotes: n/a.
Bug: None.
Change-Id: Ic841403a07941804e1605169ab0e6db481de4d42
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2429844Reviewed-by: Akihiro Ota <akihiroota@chromium.org>
Commit-Queue: Anastasia Helfinstein <anastasi@google.com>
Cr-Commit-Position: refs/heads/master@{#810737}

chrome/browser/resources/chromeos/accessibility/switch_access/nodes/basic_node.js

@@ -214,7 +214,10 @@ class BasicNode extends SAChildNode {
       case chrome.automation.RoleType.SLIDER:
         return new SliderNode(baseNode, parent);
       case chrome.automation.RoleType.TAB:
-        return TabNode.create(baseNode, parent);
+        if (baseNode.root.role === RoleType.DESKTOP) {
+          return TabNode.create(baseNode, parent);
+        }
+        // else, fall through to default case
       default:
         return new BasicNode(baseNode, parent);
     }

chrome/browser/resources/chromeos/accessibility/switch_access/switch_access_predicate.js

@@ -38,7 +38,6 @@ const SwitchAccessPredicate = {
     const defaultActionVerb = node.defaultActionVerb;
     const loc = node.location;
     const parent = node.parent;
-    const root = node.root;
     const role = node.role;
     const state = node.state;
 
@@ -60,18 +59,9 @@ const SwitchAccessPredicate = {
       return false;
     }
 
-    if (parent) {
-      // crbug.com/710559
-      // Work around for browser tabs.
-      if (role === RoleType.TAB && parent.role === RoleType.TAB_LIST &&
-          root.role === RoleType.DESKTOP) {
-        cache.isActionable.set(node, true);
-        return true;
-      }
-    }
-
     // Check various indicators that the node is actionable.
-    if (role === RoleType.BUTTON || role === RoleType.SLIDER) {
+    if (role === RoleType.BUTTON || role === RoleType.SLIDER ||
+        role === RoleType.TAB) {
       cache.isActionable.set(node, true);
       return true;
     }