google: fix spelling and go fmt

Change-Id: Ifc55814018bf66d2e77752d770a51c716376cabc

google/internal/externalaccount/sts_exchange.go

@@ -16,7 +16,7 @@ import (
 	"strings"
 )
 
-// ExchangeToken preforms a oauth2 token exchange with the provided endpoint.
+// ExchangeToken performs an oauth2 token exchange with the provided endpoint.
 // The first 4 fields are all mandatory.  headers can be used to pass additional
 // headers beyond the bare minimum required by the token exchange.  options can
 // be used to pass additional JSON-structured options to the remote server.
@@ -67,7 +67,6 @@ func ExchangeToken(ctx context.Context, endpoint string, request *STSTokenExchan
 
 	}
 
-
 	return &stsResp, nil
 }
 

google/internal/externalaccount/sts_exchange_test.go

@@ -84,8 +84,6 @@ func TestExchangeToken(t *testing.T) {
 		t.Errorf("mismatched messages received by mock server.  \nWant: \n%v\n\nGot:\n%v", expectedToken, *resp)
 	}
 
-
-
 }
 
 func TestExchangeToken_Err(t *testing.T) {
@@ -102,12 +100,15 @@ func TestExchangeToken_Err(t *testing.T) {
 		t.Errorf("Expected handled error; instead got nil.")
 	}
 }
+
 /* Lean test specifically for options, as the other features are tested earlier. */
 type testOpts struct {
 	First  string `json:"first"`
 	Second string `json:"second"`
 }
+
 var optsValues = [][]string{{"foo", "bar"}, {"cat", "pan"}}
+
 func TestExchangeToken_Opts(t *testing.T) {
 	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		body, err := ioutil.ReadAll(r.Body)