code: private void updateTintFilter() {
          if (mTint == null) {
              mTintFilter = null;
              return;
          }
          // setMode, setColor of PorterDuffColorFilter are not public method in SDK v7. (Thanks @Google still not accessible in API v24)
          // Therefore we create a new one all the time here. Don't expect this is called often.
          int color = mTint.getColorForState(getState(), Color.TRANSPARENT);
          mTintFilter = new PorterDuffColorFilter(color, mTintMode);
      }
docs: Ensures the tint filter is consistent with the current tint color and
  mode.