firefox addon - Is it possible to allow a content function to run in browser scope? -

is possible (how) addon allow specific function in document/page/content scope run in browser scope?
(i aware of security implications , specific , specific purpose.)

as general example, xmlhttprequest in content script has content scope. gm_xmlhttprequest via greasemonkey has browser scope.

imagine having gm_xmlhttprequest in content script , wanting addon allow gm_xmlhttprequest run in browser scope.

there 3 separate security scopes (called principals) involved when scripting page.

• the system principal (full access everything, including operating system apis)
• the expanded principal of sandbox may scoped 1 or more origin domains. when scoped single domain it's still considered more privileged content itself
• the content principal of page itself

so if want run addon-script performs cross-origin xhr you not need grant privilege page content itself.

you need grant sandbox in addon-script runs, separated xray-wrappers untrusted page-content.

if you're using addon sdk , xhr domains finite set can specify them in addon configuration.

if need xhrs arbitrary domains have drop lower level , use frame scripts, have system principal privileges while being able manipulate page content.

for security reasons might better use framescript instantiate sandbox principal scoped page , inject privileged xhr function it, what greasemonkey does. or if needs xhr more limited might processing outside sandbox , supply function returns processed result sandbox.