[wallet] Factor out GetWatchOnlyBalance()

src/interfaces/wallet.cpp

@@ -339,7 +339,7 @@ public:
         result.immature_balance = m_wallet.GetImmatureBalance();
         result.have_watch_only = m_wallet.HaveWatchOnly();
         if (result.have_watch_only) {
-            result.watch_only_balance = m_wallet.GetWatchOnlyBalance();
+            result.watch_only_balance = m_wallet.GetBalance(ISMINE_WATCH_ONLY);
             result.unconfirmed_watch_only_balance = m_wallet.GetUnconfirmedWatchOnlyBalance();
             result.immature_watch_only_balance = m_wallet.GetImmatureWatchOnlyBalance();
         }

src/wallet/wallet.cpp

@@ -2211,22 +2211,6 @@ CAmount CWallet::GetImmatureBalance() const
     return nTotal;
 }
 
-CAmount CWallet::GetWatchOnlyBalance() const
-{
-    CAmount nTotal = 0;
-    {
-        LOCK2(cs_main, cs_wallet);
-        for (const auto& entry : mapWallet)
-        {
-            const CWalletTx* pcoin = &entry.second;
-            if (pcoin->IsTrusted())
-                nTotal += pcoin->GetAvailableWatchOnlyCredit();
-        }
-    }
-
-    return nTotal;
-}
-
 CAmount CWallet::GetUnconfirmedWatchOnlyBalance() const
 {
     CAmount nTotal = 0;

src/wallet/wallet.h

@@ -947,7 +947,6 @@ public:
     CAmount GetBalance(const isminefilter& filter=ISMINE_SPENDABLE) const;
     CAmount GetUnconfirmedBalance() const;
     CAmount GetImmatureBalance() const;
-    CAmount GetWatchOnlyBalance() const;
     CAmount GetUnconfirmedWatchOnlyBalance() const;
     CAmount GetImmatureWatchOnlyBalance() const;
     CAmount GetLegacyBalance(const isminefilter& filter, int minDepth, const std::string* account) const;