Add a WebDocument::watchCssSelectors(selectors)

Source/core/css/resolver/StyleBuilderCustom.cpp

Index: Source/core/css/resolver/StyleBuilderCustom.cpp
diff --git a/Source/core/css/resolver/StyleBuilderCustom.cpp b/Source/core/css/resolver/StyleBuilderCustom.cpp
index 603eb7cdb9fcdbd4c769b4b792da74966a82047d..df6fe643ec3ec1dda66cc788aa4027e2468b2e24 100644
--- a/Source/core/css/resolver/StyleBuilderCustom.cpp
+++ b/Source/core/css/resolver/StyleBuilderCustom.cpp
@@ -62,6 +62,7 @@
 #include "core/css/Rect.h"
 #include "core/css/ShadowValue.h"
 #include "core/css/StylePropertySet.h"
+#include "core/css/StyleRule.h"
 #include "core/css/resolver/ElementStyleResources.h"
 #include "core/css/resolver/FilterOperationResolver.h"
 #include "core/css/resolver/FontBuilder.h"
@@ -1632,6 +1633,15 @@ void StyleBuilder::oldApplyProperty(CSSPropertyID id, StyleResolverState& state,
         state.style()->setTapHighlightColor(col);
         return;
     }
+    case CSSPropertyInternalCallback: {
+        if (isInherit || isInitial)
+            return;
+        if (primitiveValue && primitiveValue->getValueID() == CSSValueInternalPresence) {
+            state.style()->addCallbackSelector(state.currentRule()->selectorList().selectorsText());
+            return;
+        }
+        break;
+    }
     case CSSPropertyInvalid:
         return;
     // Directional properties are resolved by resolveDirectionAwareProperty() before the switch.