Add Referrer and NavigationTimeout to Page

- This prevents the train-of-calls issue.
- It might make it easier to navigate within the code for new
  contributors.

browser/mapping.go

@@ -506,8 +506,8 @@ func mapPage(vu moduleVU, p *common.Page) mapping {
 		"goForward": p.GoForward,
 		"goto": func(url string, opts goja.Value) (*goja.Promise, error) {
 			gopts := common.NewFrameGotoOptions(
-				p.MainFrame().Referrer(),
-				p.MainFrame().NavigationTimeout(),
+				p.Referrer(),
+				p.NavigationTimeout(),
 			)
 			if err := gopts.Parse(vu.Context(), opts); err != nil {
 				return nil, fmt.Errorf("parsing page navigation options to %q: %w", url, err)

common/page.go

@@ -963,6 +963,19 @@ func (p *Page) MainFrame() *Frame {
 	return mf
 }
 
+// Referrer returns the page's referrer.
+// It's an internal method not to be exposed as a JS API.
+func (p *Page) Referrer() string {
+	nm := p.mainFrameSession.getNetworkManager()
+	return nm.extraHTTPHeaders["referer"]
+}
+
+// NavigationTimeout returns the page's navigation timeout.
+// It's an internal method not to be exposed as a JS API.
+func (p *Page) NavigationTimeout() time.Duration {
+	return p.frameManager.timeoutSettings.navigationTimeout()
+}
+
 // On subscribes to a page event for which the given handler will be executed
 // passing in the ConsoleMessage associated with the event.
 // The only accepted event value is 'console'.