gddo-server: add request headers to gddoEvent

Change-Id: I70b47b3bca5fea3b160fb850a3f27e8563348b5a
Reviewed-on: https://go-review.googlesource.com/c/gddo/+/219957
Reviewed-by: Julie Qiu <julie@golang.org>

gddo-server/main.go

diff --git a/gddo-server/main.go b/gddo-server/main.go
index 4ee5f8f..f3df330 100644
--- a/gddo-server/main.go
+++ b/gddo-server/main.go
@@ -1029,6 +1029,7 @@
 	Host         string
 	Path         string
 	URL          string
+	Header       http.Header
 	RedirectHost string
 	Latency      time.Duration
 }
@@ -1039,6 +1040,7 @@
 		Host:         r.URL.Host,
 		Path:         r.URL.Path,
 		URL:          r.URL.String(),
+		Header:       r.Header,
 		RedirectHost: pkgGoDevURL.String(),
 		Latency:      latency,
 	}

gddo-server/main_test.go

diff --git a/gddo-server/main_test.go b/gddo-server/main_test.go
index dde193a..ba76b64 100644
--- a/gddo-server/main_test.go
+++ b/gddo-server/main_test.go
@@ -161,6 +161,7 @@
 			want.Latency = 100
 			want.RedirectHost = "https://" + pkgGoDevHost
 			want.URL = test.url
+			want.Header = http.Header{}
 			got := newGDDOEvent(r, want.Latency)
 			if diff := cmp.Diff(want, got); diff != "" {
 				t.Fatalf("mismatch (-want +got):\n%s", diff)