diff --git a/vendor/google.golang.org/grpc/balancer/balancer.go b/vendor/google.golang.org/grpc/balancer/balancer.go
index 1bf46aa..317c2e7 100644
--- a/vendor/google.golang.org/grpc/balancer/balancer.go
+++ b/vendor/google.golang.org/grpc/balancer/balancer.go
@@ -28,6 +28,7 @@
 
 	"google.golang.org/grpc/connectivity"
 	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/internal"
 	"google.golang.org/grpc/metadata"
 	"google.golang.org/grpc/resolver"
 )
@@ -47,6 +48,18 @@
 	m[strings.ToLower(b.Name())] = b
 }
 
+// unregisterForTesting deletes the balancer with the given name from the
+// balancer map.
+//
+// This function is not thread-safe.
+func unregisterForTesting(name string) {
+	delete(m, name)
+}
+
+func init() {
+	internal.BalancerUnregister = unregisterForTesting
+}
+
 // Get returns the resolver builder registered with the given name.
 // Note that the compare is done in a case-insenstive fashion.
 // If no builder is register with the name, nil will be returned.
diff --git a/vendor/google.golang.org/grpc/balancer/base/balancer.go b/vendor/google.golang.org/grpc/balancer/base/balancer.go
index 5f55b27..245785e 100644
--- a/vendor/google.golang.org/grpc/balancer/base/balancer.go
+++ b/vendor/google.golang.org/grpc/balancer/base/balancer.go
@@ -40,7 +40,7 @@
 
 		subConns: make(map[resolver.Address]balancer.SubConn),
 		scStates: make(map[balancer.SubConn]connectivity.State),
-		csEvltr:  &connectivityStateEvaluator{},
+		csEvltr:  &balancer.ConnectivityStateEvaluator{},
 		// Initialize picker to a picker that always return
 		// ErrNoSubConnAvailable, because when state of a SubConn changes, we
 		// may call UpdateBalancerState with this picker.
@@ -57,7 +57,7 @@
 	cc            balancer.ClientConn
 	pickerBuilder PickerBuilder
 
-	csEvltr *connectivityStateEvaluator
+	csEvltr *balancer.ConnectivityStateEvaluator
 	state   connectivity.State
 
 	subConns map[resolver.Address]balancer.SubConn
@@ -137,7 +137,7 @@
 	}
 
 	oldAggrState := b.state
-	b.state = b.csEvltr.recordTransition(oldS, s)
+	b.state = b.csEvltr.RecordTransition(oldS, s)
 
 	// Regenerate picker when one of the following happens:
 	//  - this sc became ready from not-ready
@@ -169,44 +169,3 @@
 func (p *errPicker) Pick(ctx context.Context, opts balancer.PickOptions) (balancer.SubConn, func(balancer.DoneInfo), error) {
 	return nil, nil, p.err
 }
-
-// connectivityStateEvaluator gets updated by addrConns when their
-// states transition, based on which it evaluates the state of
-// ClientConn.
-type connectivityStateEvaluator struct {
-	numReady            uint64 // Number of addrConns in ready state.
-	numConnecting       uint64 // Number of addrConns in connecting state.
-	numTransientFailure uint64 // Number of addrConns in transientFailure.
-}
-
-// recordTransition records state change happening in every subConn and based on
-// that it evaluates what aggregated state should be.
-// It can only transition between Ready, Connecting and TransientFailure. Other states,
-// Idle and Shutdown are transitioned into by ClientConn; in the beginning of the connection
-// before any subConn is created ClientConn is in idle state. In the end when ClientConn
-// closes it is in Shutdown state.
-//
-// recordTransition should only be called synchronously from the same goroutine.
-func (cse *connectivityStateEvaluator) recordTransition(oldState, newState connectivity.State) connectivity.State {
-	// Update counters.
-	for idx, state := range []connectivity.State{oldState, newState} {
-		updateVal := 2*uint64(idx) - 1 // -1 for oldState and +1 for new.
-		switch state {
-		case connectivity.Ready:
-			cse.numReady += updateVal
-		case connectivity.Connecting:
-			cse.numConnecting += updateVal
-		case connectivity.TransientFailure:
-			cse.numTransientFailure += updateVal
-		}
-	}
-
-	// Evaluate.
-	if cse.numReady > 0 {
-		return connectivity.Ready
-	}
-	if cse.numConnecting > 0 {
-		return connectivity.Connecting
-	}
-	return connectivity.TransientFailure
-}