Flame auto focus behaviour is very different from other devices, where the reference in this case is the nexus4. 1) When focusing with the flash mode set to auto or on, it turns on the flash. No other camera appears to be doing this, including the nexus4. 2) When using CAF, onAutoFocusComplete callbacks are generated by the camera service, despite no explicit auto focus requests being given. This may be related to 3). The expectation was that this would only be triggered for an application requested auto focus. This is not the case on the nexus4 for example. 3) onAutoFocusMoving transitions appear to trigger an auto focus inside the camera service. The expectation was that the application would trigger an auto focus. This is not the case on the nexus4 for example.
We've made a number of improvements to the auto-focus code recently. Discussed this with aosmond offline and we're going to close this. If it bites us again, we can reopen.