It's strange but interesting to see that all the toolbars in LibreOffice 4.2.4.2 has title bar displayed on Linux operat ing system (Debian Wheezy with KDE Plasma). However, it's easy-to-solve this problem thanks-to-the-advanced Windows configuration functionality provided by KDE.
Right-click on the title bar of LibreOffice and then click "Configure Window Behabior". In the opened dialog, select "Window Rules". Then create the rules:
Remove the title bar from all toolbars of LibreOffice.
Make ' full Screen ' toolbar with opacity 5%. Then, by pressing CTRL+SHIFT+J in Writer, i.e switch to full screen mode, the Full screen toolbar would fade out, which CR Eates a good interface for distraction free writing (see the following figure).
The Windows matched by the-the-define, because a functionality is provided by KDE that the properties of The clicked target window can automatically be extracted.