cri - use --headless=old as default.

Chrome v128 changed the default from --headless=old to --headless=new
in 2024-08. Old headless mode was effectively a separate browser render,
and while more performant did not share the same browser implementation as
headful Chrome. New headless mode will likely be useful to some, but in Quarto use cases
like printing to PDF or screenshoting, we need more work to
move to the new mode. We'll use `--headless=old` as the default for now
until the new mode is more stable, or until we really pin a version as default to be used.
This is also impacting in chromote and pagedown R packages and we could keep syncing with them.

Author: cderv

src/core/cri/cri.ts

@@ -80,7 +80,15 @@ export async function criClient(appPath?: string, port?: number) {
 
   const cmd = [
     app,
-    "--headless",
+    // TODO: Chrome v128 changed the default from --headless=old to --headless=new
+    // in 2024-08. Old headless mode was effectively a separate browser render,
+    // and while more performant did not share the same browser implementation as
+    // headful Chrome. New headless mode will likely be useful to some, but in Quarto use cases
+    // like printing to PDF or screenshoting, we need more work to
+    // move to the new mode. We'll use `--headless=old` as the default for now
+    // until the new mode is more stable, or until we really pin a version as default to be used.
+    // This is also impacting in chromote and pagedown R packages and we could keep syncing with them.
+    "--headless=old",
     "--no-sandbox",
     "--disable-gpu",
     "--renderer-process-limit=1",