Implement aria-placeholder

third_party/WebKit/Source/web/WebAXObject.cpp

Index: third_party/WebKit/Source/web/WebAXObject.cpp
diff --git a/third_party/WebKit/Source/web/WebAXObject.cpp b/third_party/WebKit/Source/web/WebAXObject.cpp
index c0e2205b9ce8bbdf3a20df8119cd9d89aff7919b..b732aabd1838fa593c19fd27cd81b4c9a9267ed4 100644
--- a/third_party/WebKit/Source/web/WebAXObject.cpp
+++ b/third_party/WebKit/Source/web/WebAXObject.cpp
@@ -978,14 +978,11 @@ WebString WebAXObject::description(
   return result;
 }
 
-WebString WebAXObject::placeholder(WebAXNameFrom nameFrom,
-                                   WebAXDescriptionFrom descriptionFrom) const {
+WebString WebAXObject::placeholder(WebAXNameFrom nameFrom) const {
   if (isDetached())
     return WebString();
 
-  return m_private->placeholder(
-      static_cast<AXNameFrom>(nameFrom),
-      static_cast<AXDescriptionFrom>(descriptionFrom));
+  return m_private->placeholder(static_cast<AXNameFrom>(nameFrom));
 }
 
 bool WebAXObject::supportsRangeValue() const {