Add WebElement::isEditable.

Source/core/dom/Node.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004-2011, 2014 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 398 matching lines @@
     virtual bool shouldHaveFocusAppearance() const;
 
     // Whether the node is inert. This can't be in Element because text nodes
     // must be recognized as inert to prevent text selection.
     bool isInert() const;
 
     enum UserSelectAllTreatment {
         UserSelectAllDoesNotAffectEditability,
         UserSelectAllIsAlwaysNonEditable
     };
-    bool isContentEditable(UserSelectAllTreatment = UserSelectAllDoesNotAffectEditability);
-    bool isContentRichlyEditable();
+    bool isContentEditable(UserSelectAllTreatment = UserSelectAllDoesNotAffectEditability) const;
+    bool isContentRichlyEditable() const;
 
     bool hasEditableStyle(EditableType editableType = ContentIsEditable, UserSelectAllTreatment treatment = UserSelectAllIsAlwaysNonEditable) const
     {
         switch (editableType) {
         case ContentIsEditable:
             return hasEditableStyle(Editable, treatment);
         case HasEditableAXRole:
             return isEditableToAccessibility(Editable);
         }
         ASSERT_NOT_REACHED();
@@ skipping 475 matching lines @@
 } // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showNode(const blink::Node*);
 void showTree(const blink::Node*);
 void showNodePath(const blink::Node*);
 #endif
 
 #endif // Node_h