fix(chromium): disable the WebUI omnibox popup preloaded at browser start

pkg/modules/chromium/browser.go

@@ -23,6 +23,25 @@ import (
 	"github.com/gotenberg/gotenberg/v8/pkg/gotenberg"
 )
 
+// chromiumDisableFeatures is the value of Chromium's --disable-features
+// switch.
+//
+// It restates the "site-per-process,Translate,BlinkGenPropertyTrees" default
+// from chromedp.DefaultExecAllocatorOptions (chromedp v0.14.2) on purpose:
+// chromedp.Flag keys its flags by switch name, so a second --disable-features
+// replaces chromedp's value instead of merging with it. Revisit this list when
+// bumping chromedp.
+//
+// WebUIOmniboxPopup and WebUIOmniboxAimPopup became enabled by default in
+// Chromium 151.0.7922.132. Their presenters build the address-bar popup WebUI
+// at browser start, headless included, which leaves a renderer process holding
+// ~85 MB of anonymous memory for a UI a PDF service can never show. Chromium
+// silently ignores feature names it does not know, so both stay harmless on
+// older builds (they exist but default to disabled on the Chromium pinned for
+// ppc64el) and once upstream eventually removes them.
+// See https://github.com/gotenberg/gotenberg/issues/1656.
+const chromiumDisableFeatures = "site-per-process,Translate,BlinkGenPropertyTrees,WebUIOmniboxPopup,WebUIOmniboxAimPopup"
+
 type browser interface {
 	gotenberg.Process
 	pdf(ctx context.Context, logger *slog.Logger, url, outputPath string, options PdfOptions, aggregate *networkAggregate) error
@@ -133,6 +152,8 @@ func (b *chromiumBrowser) Start(logger *slog.Logger) error {
 		chromedp.Flag("disable-dev-shm-usage", true),
 		// See https://github.com/gotenberg/gotenberg/issues/1293.
 		chromedp.Flag("disable-component-update", false),
+		// See https://github.com/gotenberg/gotenberg/issues/1656.
+		chromedp.Flag("disable-features", chromiumDisableFeatures),
 	)
 
 	if b.arguments.allowInsecureLocalhost {

pkg/modules/chromium/browser_test.go

@@ -3,6 +3,7 @@ package chromium
 import (
 	"context"
 	"log/slog"
+	"slices"
 	"strings"
 	"testing"
 )
@@ -37,3 +38,24 @@ func TestChromiumBrowser_Start_rejectsOverlappingStart(t *testing.T) {
 		t.Fatal("expected the browser to stay not started")
 	}
 }
+
+// TestChromiumDisableFeatures guards the override described in
+// https://github.com/gotenberg/gotenberg/issues/1656. Gotenberg replaces
+// chromedp's --disable-features value rather than extending it, as
+// chromedp.Flag keys its flags by switch name. Dropping one of chromedp's own
+// entries while editing this list would silently re-enable it.
+func TestChromiumDisableFeatures(t *testing.T) {
+	for _, feature := range []string{
+		// chromedp.DefaultExecAllocatorOptions.
+		"site-per-process",
+		"Translate",
+		"BlinkGenPropertyTrees",
+		// The address-bar popup WebUI, built even in headless.
+		"WebUIOmniboxPopup",
+		"WebUIOmniboxAimPopup",
+	} {
+		if !slices.Contains(strings.Split(chromiumDisableFeatures, ","), feature) {
+			t.Errorf("expected %q to be disabled, got %q", feature, chromiumDisableFeatures)
+		}
+	}
+}