queryCommandSupported() should return 'true' for cut/copy/paste editing commands

Source/core/editing/Editor.h

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 111 matching lines @@
 
     class CORE_EXPORT Command {
         STACK_ALLOCATED();
     public:
         Command();
         Command(const EditorInternalCommand*, EditorCommandSource, PassRefPtrWillBeRawPtr<LocalFrame>);
 
         bool execute(const String& parameter = String(), Event* triggeringEvent = nullptr) const;
         bool execute(Event* triggeringEvent) const;
 
-        bool isSupported() const;
+        bool isSupported(bool enabled = false) const;

[dcheng, 2015/04/20 17:09:03]

I don't really understand why we added this default arg. It seems wrong.

[Abhijeet Kandalkar Slow, 2015/04/21 14:14:33]

current implementation of isSupported() check whether javaScript can access
clipboard. As it is not allowed it is returning false. 
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...

isSupported() should only check whether command is present in CommandMap. If
command is supported, isEnabled() should check whether is it actually available
to use.

Default flag is added to identify whether isSupported() is invoked by
isEnabled(). If it is invoked by isEnabled() then only check whether javaScript
can access clipboard.

         bool isEnabled(Event* triggeringEvent = nullptr) const;
 
         TriState state(Event* triggeringEvent = nullptr) const;
         String value(Event* triggeringEvent = nullptr) const;
 
         bool isTextInsertion() const;
 
         // Returns 0 if this Command is not supported.
         int idForHistogram() const;
     private:
@@ skipping 157 matching lines @@
 
 inline bool Editor::markedTextMatchesAreHighlighted() const
 {
     return m_areMarkedTextMatchesHighlighted;
 }
 
 
 } // namespace blink
 
 #endif // Editor_h