POSIX: make sure that we never pass directory descriptors into the sandbox.

BUG=43304

http://codereview.chromium.org/2733011/show

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@49446 0039d316-1c4b-4281-b951-d872f2087c98
RenderSandboxHostLinux::~RenderSandboxHostLinux() {
  if (init_) {
    if (HANDLE_EINTR(close(renderer_socket_)) < 0)
      PLOG(ERROR) << "close";
    if (HANDLE_EINTR(close(childs_lifeline_fd_)) < 0)
      PLOG(ERROR) << "close";
  }
}

RenderSandboxHostLinux::~RenderSandboxHostLinux() {
  if (init_) {
    if (HANDLE_EINTR(close(renderer_socket_)) < 0)
      PLOG(ERROR) << "close";
    if (HANDLE_EINTR(close(childs_lifeline_fd_)) < 0)
      PLOG(ERROR) << "close";
  }
}
