Remove duplicate extension update calls to the wallet.

Make the StoredPaymentChannel{Client|Server}States in charge of notifying the
wallet when the stored state has changed. Reduced the duplicate calls to update
and subsequently save the wallet to disk.

core/src/main/java/org/bitcoinj/protocols/channels/PaymentChannelClientState.java

@@ -216,7 +216,6 @@ public class PaymentChannelClientState {
         StoredPaymentChannelClientStates channels = (StoredPaymentChannelClientStates)
                 wallet.getExtensions().get(StoredPaymentChannelClientStates.EXTENSION_ID);
         channels.removeChannel(storedChannel);
-        wallet.addOrUpdateExtension(channels);
         storedChannel = null;
     }
 
@@ -450,7 +449,7 @@ public class PaymentChannelClientState {
         storedChannel.valueToMe = valueToMe;
         StoredPaymentChannelClientStates channels = (StoredPaymentChannelClientStates)
                 wallet.getExtensions().get(StoredPaymentChannelClientStates.EXTENSION_ID);
-        wallet.addOrUpdateExtension(channels);
+        channels.updatedChannel(storedChannel);
     }
 
     /**
@@ -486,7 +485,6 @@ public class PaymentChannelClientState {
         checkState(channels.getChannel(id, multisigContract.getHash()) == null);
         storedChannel = new StoredClientChannel(id, multisigContract, refundTx, myKey, valueToMe, refundFees, true);
         channels.putChannel(storedChannel);
-        wallet.addOrUpdateExtension(channels);
     }
 
     /**

core/src/main/java/org/bitcoinj/protocols/channels/PaymentChannelServerState.java

@@ -473,7 +473,7 @@ public class PaymentChannelServerState {
             storedServerChannel.updateValueToMe(bestValueToMe, bestValueSignature);
             StoredPaymentChannelServerStates channels = (StoredPaymentChannelServerStates)
                     wallet.getExtensions().get(StoredPaymentChannelServerStates.EXTENSION_ID);
-            wallet.addOrUpdateExtension(channels);
+            channels.updatedChannel(storedServerChannel);
         }
     }
 
@@ -500,6 +500,5 @@ public class PaymentChannelServerState {
         if (connectedHandler != null)
             checkState(storedServerChannel.setConnectedHandler(connectedHandler, false) == connectedHandler);
         channels.putChannel(storedServerChannel);
-        wallet.addOrUpdateExtension(channels);
     }
 }

core/src/main/java/org/bitcoinj/protocols/channels/StoredPaymentChannelClientStates.java

@@ -179,6 +179,15 @@ public class StoredPaymentChannelClientStates implements WalletExtension {
         }
     }
 
+    /**
+     * Notifies the set of stored states that a channel has been updated. Use to notify the wallet of an update to this
+     * wallet extension.
+     */
+    void updatedChannel(final StoredClientChannel channel) {
+        log.info("Stored client channel {} was updated", channel.hashCode());
+        containingWallet.addOrUpdateExtension(this);
+    }
+
     /**
      * Adds the given channel to this set of stored states, broadcasting the contract and refund transactions when the
      * channel expires and notifies the wallet of an update to this wallet extension
@@ -206,7 +215,7 @@ public class StoredPaymentChannelClientStates implements WalletExtension {
             lock.unlock();
         }
         if (updateWallet)
-            containingWallet.addOrUpdateExtension(this);
+            updatedChannel(channel);
     }
 
     /**
@@ -242,7 +251,7 @@ public class StoredPaymentChannelClientStates implements WalletExtension {
         } finally {
             lock.unlock();
         }
-        containingWallet.addOrUpdateExtension(this);
+        updatedChannel(channel);
     }
 
     @Override

core/src/main/java/org/bitcoinj/protocols/channels/StoredPaymentChannelServerStates.java

@@ -116,7 +116,7 @@ public class StoredPaymentChannelServerStates implements WalletExtension {
             }
             channel.state = null;
         }
-        wallet.addOrUpdateExtension(this);
+        updatedChannel(channel);
     }
 
     /**
@@ -149,6 +149,15 @@ public class StoredPaymentChannelServerStates implements WalletExtension {
         }
     }
 
+    /**
+     * Notifies the set of stored states that a channel has been updated. Use to notify the wallet of an update to this
+     * wallet extension.
+     */
+    public void updatedChannel(final StoredServerChannel channel) {
+        log.info("Stored server channel {} was updated", channel.hashCode());
+        wallet.addOrUpdateExtension(this);
+    }
+
     /**
      * <p>Puts the given channel in the channels map and automatically closes it 2 hours before its refund transaction
      * becomes spendable.</p>
@@ -174,6 +183,7 @@ public class StoredPaymentChannelServerStates implements WalletExtension {
         } finally {
             lock.unlock();
         }
+        updatedChannel(channel);
     }
 
     @Override