VAD refactoring: Added function for repeated code.
VAD refactoring: Added function for repeated code.

Added WeightedAverage() to calculate global mean. This removes hard coded Gaussian model size and repeated code.

Tested with vad_unittests, audioproc_unittest and trybots.

BUG=None
TEST=None

Review URL: https://webrtc-codereview.appspot.com/571006

git-svn-id: 917f5d3ca488f358c4d40eaec14422cf392ccec9@2275 4adac7df-926f-26a2-2b94-8c16560cd09d

mwgoldsmith/ilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,mwgoldsmith/ilbc,ShiftMediaProject/libilbc,mwgoldsmith/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,mwgoldsmith/libilbc,mwgoldsmith/ilbc,ShiftMediaProject/libilbc,mwgoldsmith/ilbc,mwgoldsmith/libilbc,mwgoldsmith/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc