Using a Bitcoin-Qt v0.16.0 ([downloaded from bitcoin page](https://bitcoin.org/bin/bitcoin-core-0.16.0/bitcoin-0.16.0-osx.dmg)) in an macOS High Sierra 10.13.4 

When I start after a fresh install Bitcoin-Qt as a mainnet node and wallet, the wallet prompt that about 203gb is going to be used in my disk
![image](https://user-images.githubusercontent.com/20187136/39899688-ba820bfe-5493-11e8-87d9-460ed5716a02.png)

When I start the node and wallet as testnet, shows the same message about the 203gb disk usage
![image](https://user-images.githubusercontent.com/20187136/39899756-17b31214-5494-11e8-8a57-60e604e74afb.png)

It seems that the second time the message is wrong, due that the testnet database uses about 14gb.
int64_t getTotalBytesSent() override { return g_connman ? g_connman->GetTotalBytesSent() : 0; }
    size_t getMempoolSize() override { return ::mempool.size(); }
    size_t getMempoolDynamicUsage() override { return ::mempool.DynamicMemoryUsage(); }
    bool getHeaderTip(int& height, int64_t& block_time) override
    {
        LOCK(::cs_main);
        if (::pindexBestHeader) {
            height = ::pindexBestHeader->nHeight;
            block_time = ::pindexBestHeader->GetBlockTime();
            return true;
        }
        return false;
    }
    int getNumBlocks() override
    {
        LOCK(::cs_main);
        return ::chainActive.Height();
    }
    int64_t getLastBlockTime() override
    {
        LOCK(::cs_main);
        if (::chainActive.Tip()) {
            return ::chainActive.Tip()->GetBlockTime();
        }
        return Params().GenesisBlock().GetBlockTime(); 
    }
    double getVerificationProgress() override