GlobalScope::from_context does not handle a null global object

[jdm]

servo/components/script/dom/globalscope.rs

Lines 1297 to 1302 in bac9903

	/// Returns the global scope for the given JSContext
	#[allow(unsafe_code)]
	pub unsafe fn from_context(cx: *mut JSContext) -> DomRoot<Self> {
	let global = CurrentGlobalOrNull(cx);
	global_scope_from_global(global, cx)
	}

It calls CurrentGlobalOrNull, but the return type is a DomRoot<GlobalScope>. In the short term adding an assert that the result is not null would be more safe than a segfault.

[jdm]

I think the best way to improve this would be to add an InCompartment argument to the method, as I describe in #25369 (comment).