How do I disable overlay scrollbars?

export LIBOVERLAY_SCROLLBAR=0

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export LIBOVERLAY_SCROLLBAR=0

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sudo apt-get remove overlay-scrollbar liboverlay-scrollbar

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Ubuntu 12.04
gsettings set org.gnome.desktop.interface ubuntu-overlay-scrollbars false
gsettings reset org.gnome.desktop.interface ubuntu-overlay-scrollbars

Ubuntu 12.10
gsettings set com.canonical.desktop.interface scrollbar-mode normal
gsettings reset com.canonical.desktop.interface scrollbar-mode