Remove more Node API.

sky/engine/core/rendering/RenderObject.cpp

Index: sky/engine/core/rendering/RenderObject.cpp
diff --git a/sky/engine/core/rendering/RenderObject.cpp b/sky/engine/core/rendering/RenderObject.cpp
index df6bb399e5e2e28bc856964604d6704080fec855..e9b81bf34b25a02930062ed847a6eedd04538af7 100644
--- a/sky/engine/core/rendering/RenderObject.cpp
+++ b/sky/engine/core/rendering/RenderObject.cpp
@@ -1572,7 +1572,7 @@ void RenderObject::showRenderTreeAndMark(const RenderObject* markedObject1, cons
 
 bool RenderObject::isSelectable() const
 {
-    return !isInert() && !(style()->userSelect() == SELECT_NONE && style()->userModify() == READ_ONLY);
+    return !(style()->userSelect() == SELECT_NONE && style()->userModify() == READ_ONLY);
 }
 
 Color RenderObject::selectionBackgroundColor() const
@@ -2380,14 +2380,6 @@ int RenderObject::nextOffset(int current) const
     return current + 1;
 }
 
-bool RenderObject::isInert() const
-{
-    const RenderObject* renderer = this;
-    while (!renderer->node())
-        renderer = renderer->parent();
-    return renderer->node()->isInert();
-}
-
 // touch-action applies to all elements with both width AND height properties.
 // According to the CSS Box Model Spec (http://dev.w3.org/csswg/css-box/#the-width-and-height-properties)
 // width applies to all elements but non-replaced inline elements, table rows, and row groups and