An unknown role is considered a bug, should never occur

third_party/WebKit/Source/modules/accessibility/AXObjectImpl.cpp

Index: third_party/WebKit/Source/modules/accessibility/AXObjectImpl.cpp
diff --git a/third_party/WebKit/Source/modules/accessibility/AXObjectImpl.cpp b/third_party/WebKit/Source/modules/accessibility/AXObjectImpl.cpp
index 37699ded8eb6daca5aa78529441b7caa1843913c..37a136369da5de990baaf1f4b514933fb1d10d54 100644
--- a/third_party/WebKit/Source/modules/accessibility/AXObjectImpl.cpp
+++ b/third_party/WebKit/Source/modules/accessibility/AXObjectImpl.cpp
@@ -1986,9 +1986,13 @@ bool AXObjectImpl::NameFromContents(bool recursive) const {
     case kRowRole:
     case kRubyRole:
     case kRulerRole:
+      result = recursive || (CanReceiveAccessibilityFocus() && !IsEditable());
+      break;
+
     case kUnknownRole:
     case kNumRoles:
-      result = recursive || (CanReceiveAccessibilityFocus() && !IsEditable());
+      LOG(ERROR) << "kUnknownRole for " << GetNode();
+      NOTREACHED();
       break;
   }