setSize(size) {
    if (equals(size, this.size_)) {
      return;
    }
    this.size_[0] = size[0];
    this.size_[1] = size[1];
    this.updateSize_();
  }
Changes the size of the render target texture. Note: will do nothing if the size
is already the same.
@param {Array<number>} size Expected size of the render target texture