Add FID deprecation warn when first browser start

When the first browser instance (chrome) is started or connected to, we
want to log a warning that FID has been deprecated and INP is the web
vital to work with now.

Author: ankur22

internal/js/modules/k6/browser/browser/registry.go

@@ -184,6 +184,8 @@ type browserRegistry struct {
 
 type browserBuildFunc func(ctx, vuCtx context.Context) (*common.Browser, error)
 
+var fidDeprecationWarningOnce sync.Once
+
 // newBrowserRegistry should only take a background context, not a context from
 // k6 (i.e. vu). The reason for this is that we want to control the chromium
 // lifecycle with the k6 event system.
@@ -208,6 +210,10 @@ func newBrowserRegistry(
 			wsURL, isRemoteBrowser = remote.isRemoteBrowser()
 		)
 
+		fidDeprecationWarningOnce.Do(func() {
+			vu.State().Logger.Warnf("FID has been deprecated and superseded by INP -- https://web.dev/blog/fid")
+		})
+
 		if isRemoteBrowser {
 			b, err = bt.Connect(ctx, vuCtx, wsURL)
 			if err != nil {

internal/js/modules/k6/browser/common/frame_session.go

@@ -36,8 +36,6 @@ import (
 
 const utilityWorldName = "__k6_browser_utility_world__"
 
-var fidDeprecationWarningOnce sync.Once
-
 // CPUProfile is used in throttleCPU.
 type CPUProfile struct {
 	// rate as a slowdown factor (1 is no throttle, 2 is 2x slowdown, etc).
@@ -347,10 +345,6 @@ func (fs *FrameSession) parseAndEmitWebVitalMetric(object string) error {
 		return fmt.Errorf("json couldn't be parsed: %w", err)
 	}
 
-	fidDeprecationWarningOnce.Do(func() {
-		fs.logger.Warnf("FrameSession:parseAndEmitWebVitalMetric", "FID has been deprecated and superseded by INP -- https://web.dev/blog/fid")
-	})
-
 	metric, ok := fs.k6Metrics.WebVitals[wv.Name]
 	if !ok {
 		return fmt.Errorf("metric not registered %q", wv.Name)