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 5ecd1bb5f08b404ae5f798b4f5d96970e38d32e9..8518ee4286a67e2cd28425cdedd5b67c5b466521 100644
--- a/Source/core/css/resolver/StyleBuilderCustom.cpp
+++ b/Source/core/css/resolver/StyleBuilderCustom.cpp
@@ -785,6 +785,24 @@ void StyleBuilder::oldApplyProperty(CSSPropertyID id, StyleResolver* styleResolv
         state.style()->setTapHighlightColor(col);
         return;
     }
+#if ENABLE(CSS_CALLBACKS)
+    case CSSPropertyInternalCallback: {
+        if (isInherit || isInitial)
+            return;
+        if (primitiveValue) {

[esprehn, 2013/07/13 01:43:01]

if (primitiveValue && primitiveValue->getValueID())
  state.style()->addCallbackSelector( ... );

Since you only allow one value would be simpler

[Jeffrey Yasskin, 2013/08/13 00:29:29]

Done.

+            switch (primitiveValue->getValueID()) {
+            case CSSValueInternalPresence:
+                state.style()->addCallbackSelector(
+                    state.rule()->selectorList().selectorsText(),
+                    state.element()->document());
+                return;
+            default:
+                break;
+            }
+        }
+        break;
+    }
+#endif
     case CSSPropertyInvalid:
         return;
     // Directional properties are resolved by resolveDirectionAwareProperty() before the switch.