Rename Channels#onChannelMessage

As part of #1293 (making ICipher.decrypt asynchronous), we will be
making this method async, and another method will wish to wait on its
completion. As such, this should no longer be named as if it were only
an informative callback.

src/common/lib/client/realtime.ts

@@ -83,12 +83,12 @@ class Channels extends EventEmitter {
     }
   }
 
-  onChannelMessage(msg: ProtocolMessage) {
+  processChannelMessage(msg: ProtocolMessage) {
     const channelName = msg.channel;
     if (channelName === undefined) {
       Logger.logAction(
         Logger.LOG_ERROR,
-        'Channels.onChannelMessage()',
+        'Channels.processChannelMessage()',
         'received event unspecified channel, action = ' + msg.action
       );
       return;
@@ -97,7 +97,7 @@ class Channels extends EventEmitter {
     if (!channel) {
       Logger.logAction(
         Logger.LOG_ERROR,
-        'Channels.onChannelMessage()',
+        'Channels.processChannelMessage()',
         'received event for non-existent channel: ' + channelName
       );
       return;

src/common/lib/transport/connectionmanager.ts

@@ -1973,13 +1973,13 @@ class ConnectionManager extends EventEmitter {
      * before it's become active (while waiting for the old one to become
      * idle), message can validly arrive on it even though it isn't active */
     if (onActiveTransport || onUpgradeTransport) {
-      this.realtime.channels.onChannelMessage(message);
+      this.realtime.channels.processChannelMessage(message);
     } else {
       // Message came in on a defunct transport. Allow only acks, nacks, & errors for outstanding
       // messages,  no new messages (as sync has been sent on new transport so new messages will
       // be resent there, or connection has been closed so don't want new messages)
       if (Utils.arrIndexOf([actions.ACK, actions.NACK, actions.ERROR], message.action) > -1) {
-        this.realtime.channels.onChannelMessage(message);
+        this.realtime.channels.processChannelMessage(message);
       } else {
         Logger.logAction(
           Logger.LOG_MICRO,