Update the comment for ReplacedHandle

    bool mustValidateDisplay(Display display);

    // When a buffer in the cache is replaced by a new one, we must keep it

    // alive until it has been replaced in ComposerHal.

    // alive until it has been replaced in ComposerHal because it is still using

    // the old buffer.

    class ReplacedHandle {

      public:

        explicit ReplacedHandle(bool isBuffer) : mIsBuffer(isBuffer) {}