Revert "add backoff"

This reverts commit 4a5ab5b.

internal/resolver/delegatingresolver/delegatingresolver_test.go

@@ -110,7 +110,6 @@ func (s) TestDelegatingResolverNoProxy(t *testing.T) {
 	if err != nil || dr == nil {
 		t.Fatalf("Failed to create delegating resolver: %v", err)
 	}
-	t.Cleanup(func() { dr.Close() })
 
 	// Update the manual resolver with a test address.
 	mr.UpdateState(resolver.State{
@@ -163,7 +162,6 @@ func (s) TestDelegatingResolverwithDNSAndProxyWithTargetResolution(t *testing.T)
 
 	tcc, stateCh, _ := createTestResolverClientConn(t)
 	dr, err := New(resolver.Target{URL: *testutils.MustParseURL(target)}, tcc, resolver.BuildOptions{}, mrTarget, true)
-	t.Cleanup(func() { dr.Close() })
 	if err != nil {
 		t.Fatalf("Failed to create delegating resolver: %v", err)
 	}
@@ -220,7 +218,6 @@ func (s) TestDelegatingResolverwithDNSAndProxyWithNoTargetResolution(t *testing.
 	if dr == nil {
 		t.Fatalf("Failed to create delegating resolver")
 	}
-	t.Cleanup(func() { dr.Close() })
 
 	mrProxy.UpdateState(resolver.State{
 		Addresses:     []resolver.Address{{Addr: resolvedProxyTestAddr}},
@@ -241,7 +238,7 @@ func (s) TestDelegatingResolverwithDNSAndProxyWithNoTargetResolution(t *testing.
 // correctly updates state with resolved proxy address and custom resolved target
 // address as the attributes when the target URI scheme is not DNS and a proxy is
 // configured.
-func (s)TestDelegatingResolverwithCustomResolverAndProxy(t *testing.T) {
+func (s) TestDelegatingResolverwithCustomResolverAndProxy(t *testing.T) {
 	hpfe := func(req *http.Request) (*url.URL, error) {
 		if req.URL.Host == targetTestAddr {
 			return &url.URL{
@@ -252,13 +249,13 @@ func (s)TestDelegatingResolverwithCustomResolverAndProxy(t *testing.T) {
 		return nil, nil
 	}
 	defer overwrite(hpfe)()
+
 	mrTarget := manual.NewBuilderWithScheme("test") // Manual resolver to control the target resolution.
 	mrProxy := setupDNS(t)                          // Set up a manual DNS resolver to control the proxy address resolution.
 	target := "test:///" + targetTestAddr
 
 	tcc, stateCh, _ := createTestResolverClientConn(t)
 	dr, err := New(resolver.Target{URL: *testutils.MustParseURL(target)}, tcc, resolver.BuildOptions{}, mrTarget, false)
-	// t.Cleanup(func() { dr.Close() })
 	if err != nil {
 		t.Fatalf("Failed to create delegating resolver: %v", err)
 	}
@@ -301,9 +298,8 @@ func (s)TestDelegatingResolverwithCustomResolverAndProxy(t *testing.T) {
 	},
 		ServiceConfig: &serviceconfig.ParseResult{},
 	}
-	dr.Close()
+
 	if state := <-stateCh; len(state.Addresses) != 4 || !cmp.Equal(expectedState, state) {
 		t.Fatalf("Unexpected state from delegating resolver: %v\n, want %v\n", state, expectedState)
 	}
-
 }