Check all ancestor navigable trustworthiness for mixed content (#36157)

Propagate through documents a flag that represents if any of the
ancestor navigables has a potentially trustworthy origin.

The "potentially trustworthy origin" concept appears to have gotten
confused in a couple of places and we were instead testing if a URL had
"potentially trustworthy" properties.

The main test for the ancestor navigables is
[mixed-content/nested-iframes](https://github.com/web-platform-tests/wpt/blob/master/mixed-content/nested-iframes.window.js)

---
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- [X] `./mach build -d` does not report any errors
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- [X] These changes fix #36108 

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---------

Signed-off-by: Sebastian C <sebsebmc@gmail.com>

components/script/dom/htmllinkelement.rs

@@ -82,6 +82,7 @@ struct LinkProcessingOptions {
     source_set: Option<()>,
     base_url: ServoUrl,
     insecure_requests_policy: InsecureRequestsPolicy,
+    has_trustworthy_ancestor_origin: bool,
     // Some fields that we don't need yet are missing
 }
 
@@ -335,6 +336,7 @@ impl HTMLLinkElement {
             source_set: None, // FIXME
             base_url: document.borrow().base_url(),
             insecure_requests_policy: document.insecure_requests_policy(),
+            has_trustworthy_ancestor_origin: document.has_trustworthy_ancestor_or_current_origin(),
         };
 
         // Step 3. If el has an href attribute, then set options's href to the value of el's href attribute.
@@ -669,6 +671,7 @@ impl LinkProcessingOptions {
             None,
             Referrer::NoReferrer,
             self.insecure_requests_policy,
+            self.has_trustworthy_ancestor_origin,
         )
         .integrity_metadata(self.integrity)
         .policy_container(self.policy_container)