--- build/linux/unbundle/libpng.gn.orig	2025-12-10 15:04:57 UTC
+++ build/linux/unbundle/libpng.gn
@@ -21,3 +21,27 @@ source_set("libpng") {
   deps = [ ":libpng_shim" ]
   public_configs = [ ":libpng_config" ]
 }
+
+libpng_testonly_visibility = [
+  "//chrome/test:accessibility_live_site_tests",
+  "//chrome/test:captured_sites_interactive_tests",
+  "//chrome/test:interactive_ui_tests",
+  "//tools/imagediff",
+
+  # Using a wildcard, to cover template-generated targets (e.g.
+  # `run_libpng_progressive_read_fuzzer` on `ios-catalyst` trybot).
+  "//testing/libfuzzer/fuzzers:*",
+
+  # Using a wildcard, to cover template-generated targets (e.g.
+  # `//ui/gfx:gfx_unittests__library__jni_registration__native_sources` or
+  # `//ui/gfx:gfx_unittests__exec`).
+  "//ui/gfx:*",
+]
+
+group("libpng_for_testonly") {
+  testonly = true
+  public_deps = [ ":libpng" ]
+
+  visibility = []
+  visibility = libpng_testonly_visibility
+}