[gentoo-user] What does the "sqlite" USE flag do in Firefox?

[Nikos Chantziaras]

Can someone enlighten me as to what exactly the "sqlite" USE flag does 
for xulrunner and firefox?  AFAIK, it seems to make use of the system's 
sqlite instead of bundled sqlite.  Which seems saner.  But recently, the 
default in the ebuild seems to be -sqlite (preferring the bundled lib).

Why?