DecryptStream: Use Ref instead of two integers

Follow the changes introduced before also in this new code.
6 jobs for implement-crypto-using-NSS in 7 minutes and 29 seconds (queued for 2 seconds)
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passed #525489
build

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passed #525494
build_android

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passed #525490
build_clang_libcpp

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passed #525493
build_clazy

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passed #525492
build_mingw64_fedora

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passed #525491
build_ubuntu_16_04

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