The current algorithm for selecting the ScriptProcessor bufferSize value when the caller uses a value of 0 is very, very conservative.  It basically takes 4 times the callback size, rounded up to a power of two.

This needs to be platform-specific.  On desktop, it's probably good enough to just double the callback size (rounding up to a power of two).  This means a value of 256 or 512 on mac, 1024 on linux because the callback size is 128 or 256 on mac and 512 on linux.  Windows is 10 ms---about 440 frames.  1024 is probably a good choice.

For android, the variety of HW devices makes this challenging.  Currently on Android, the callback size is at least 2048.  For some devices like a Nexus 9, this is probably way too big and should be lowered (but that's a different bug).  It's probably ok for now to do same as desktop above.  But this needs testing which might be hard to do before landing the changes.