mozilla-b2g/gaia — pull request #8643 by norci (2013-03-14 07:41:55+00:00)
Title: Bug 847680 wrong camera orientation change

in file
/gecko/widget/gonk/OrientationObserver.cpp : 197
void OrientationObserver::Notify(const hal::SensorData& aSensorData)

we can see the right logic for orientation change.