channelz: major cleanup / reorganization (#6969)

Author: dfawley

balancer/balancer.go

@@ -232,8 +232,8 @@ type BuildOptions struct {
 	// implementations which do not communicate with a remote load balancer
 	// server can ignore this field.
 	Authority string
-	// ChannelzParentID is the parent ClientConn's channelz ID.
-	ChannelzParentID *channelz.Identifier
+	// ChannelzParent is the parent ClientConn's channelz channel.
+	ChannelzParent channelz.Identifier
 	// CustomUserAgent is the custom user agent set on the parent ClientConn.
 	// The balancer should set the same custom user agent if it creates a
 	// ClientConn.

balancer/grpclb/grpclb_remote_balancer.go

@@ -246,7 +246,7 @@ func (lb *lbBalancer) newRemoteBalancerCCWrapper() error {
 	// Explicitly set pickfirst as the balancer.
 	dopts = append(dopts, grpc.WithDefaultServiceConfig(`{"loadBalancingPolicy":"pick_first"}`))
 	dopts = append(dopts, grpc.WithResolvers(lb.manualResolver))
-	dopts = append(dopts, grpc.WithChannelzParentID(lb.opt.ChannelzParentID))
+	dopts = append(dopts, grpc.WithChannelzParentID(lb.opt.ChannelzParent))
 
 	// Enable Keepalive for grpclb client.
 	dopts = append(dopts, grpc.WithKeepaliveParams(keepalive.ClientParameters{