CSS4: Implement :placeholder-shown pseudo class

Source/core/testing/Internals.cpp

Index: Source/core/testing/Internals.cpp
diff --git a/Source/core/testing/Internals.cpp b/Source/core/testing/Internals.cpp
index 070d3bf3dca55b5c8119e4e9d8335a1991d2a604..22db66276e8bc4362b4d993095fa55c4b051696e 100644
--- a/Source/core/testing/Internals.cpp
+++ b/Source/core/testing/Internals.cpp
@@ -687,8 +687,11 @@ const AtomicString& Internals::shadowPseudoId(Element* element)
 String Internals::visiblePlaceholder(Element* element)
 {
     if (element && isHTMLTextFormControlElement(*element)) {
-        if (toHTMLTextFormControlElement(element)->placeholderShouldBeVisible())
-            return toHTMLTextFormControlElement(element)->placeholderElement()->textContent();
+        const HTMLTextFormControlElement& textFormControlElement = toHTMLTextFormControlElement(*element);
+        if (!textFormControlElement.isPlaceholderVisible())
+            return String();
+        if (HTMLElement* placeholderElement = textFormControlElement.placeholderElement())
+            return placeholderElement->textContent();
     }
 
     return String();