1401640 - Do unpacked extension checks off the main thread

Status: NEW

(WebExtensions :: Request Handling, enhancement, P3)

Description

[Haik Aftandilian [:haik]]

For unpacked developer extensions (i.e., when an extension developer loads an extension from a directory and not a JAR file) ExtensionProtocolHandler::NewStream() does some checks to make sure the moz-extension URI it loads on behalf of child processes resolves to a file within the directory. Specifically, it calls nsIFile::Normalize() and widget::WinUtils::ResolveJunctionPointsAndSymLinks() which would be better to do off the main thread. On Mac and Linux, nsIFile::Normalize() calls realpath(3). This code is also used for system extensions when Firefox is run from a developer repo (as in ./mach run.)