Merge "Clear effect buffer before sending to chain" into lmp-dev

    if (getEffectChain_l(AUDIO_SESSION_OUTPUT_MIX) != 0) {

        mEffectBufferValid = true;

        // as long as there are effects we should clear the effects buffer, to avoid

        // passing a non-clean buffer to the effect chain

        memset(mEffectBuffer, 0, mEffectBufferSize);

    }

    // sink or mix buffer must be cleared if all tracks are connected to an

            // must imply MIXER_TRACKS_READY.

            // Later, we may clear buffers regardless, and skip much of this logic.

        }

        // TODO - either mEffectBuffer or mSinkBuffer needs to be cleared.

        if (mEffectBufferValid) {

            memset(mEffectBuffer, 0, mEffectBufferSize);

        }

        // FIXME as a performance optimization, should remember previous zero status

        memset(mSinkBuffer, 0, mNormalFrameCount * mFrameSize);

    }