Bug 288057 – [WebDriver][BiDi] Implement the script.addPreloadScript command

• Status: RESOLVED
• Resolution: FIXED
• Component: WebDriver

[Lauro Moura]

https://w3c.github.io/webdriver-bidi/#command-script-addPreloadScript

One of the cornerstones used by clients to make the browser to push custom messages through the `channels`, delivered as `script.message` events.

[Radar WebKit Bug Importer]

<rdar://problem/145716105>

[Serge Deh]

Some defensive ideas for resource limits to prevent potential denial of service issues with preload scripts:

1. **Maximum number of preload scripts per session**
   - Cap number of preload scripts per session?
   - This would prevent memory exhaustion from unbounded script accumulation
   - We'd need to return an appropriate BiDi error when the limit is exceeded
2. **Maximum function declaration length**
   - Cap size of function declaration
   - Prevents processing extremely large script payloads
   - Helps protect against memory and parsing overhead attacks
3. **Total memory limit for all preload scripts**
   - An aggregate limit across all preload scripts in a session
   - Could track both source code size and runtime overhead
   - Prevents cumulative memory exhaustion

[EWS]

Committed 310815@main (17a80254d05d): <https://commits.webkit.org/310815@main>

Reviewed commits have been landed. Closing PR #57773 and removing active labels.