Enable the DesktopAuraTopLevelOwnedPopupResizeTest test for Linux AURA.

Added implementation for the DesktopRootWindowHostX11::SetSize function.

BUG=330596
R=erg@chromium.org, sky@chromium.org

Review URL: https://codereview.chromium.org/127453002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243740 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 243740