isSupported      4239 Source/core/dom/Document.cpp     return command(this, commandName).isSupported();
isSupported       144 Source/core/editing/Editor.h         bool isSupported() const;
isSupported      1682 Source/core/editing/EditorCommand.cpp         if (!isSupported() || !m_frame || !m_command->allowExecutionWhenDisabled)
isSupported      1712 Source/core/editing/EditorCommand.cpp     if (!isSupported() || !m_frame)
isSupported      1719 Source/core/editing/EditorCommand.cpp     if (!isSupported() || !m_frame)
isSupported      1726 Source/core/editing/EditorCommand.cpp     if (!isSupported() || !m_frame)