Auto merge of #26450 - PeterZhizhin:add_referrerpolicy_to_list_of_relevant_mutations, r=jdm

Add referrerpolicy to list of relevant mutations

<!-- Please describe your changes on the following line: -->

`img.referrerPolicy` change now mutates the image.
Not all `referrerPolicy` attribute changes result in an image update event.
Only valid changes are reflected.

All referrerpolicy tests inside `relevant-mutations.html` WPT test now pass.

---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `___` with appropriate data: -->
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix #26388

<!-- Either: -->
- [x] These have tests:
```
./mach test-wpt tests/wpt/web-platform-tests/html/semantics/embedded-content/the-img-element/relevant-mutations.html
```

components/net_traits/lib.rs

@@ -126,6 +126,22 @@ pub enum ReferrerPolicy {
     StrictOriginWhenCrossOrigin,
 }
 
+impl ToString for ReferrerPolicy {
+    fn to_string(&self) -> String {
+        match self {
+            ReferrerPolicy::NoReferrer => "no-referrer",
+            ReferrerPolicy::NoReferrerWhenDowngrade => "no-referrer-when-downgrade",
+            ReferrerPolicy::Origin => "origin",
+            ReferrerPolicy::SameOrigin => "same-origin",
+            ReferrerPolicy::OriginWhenCrossOrigin => "origin-when-cross-origin",
+            ReferrerPolicy::UnsafeUrl => "unsafe-url",
+            ReferrerPolicy::StrictOrigin => "strict-origin",
+            ReferrerPolicy::StrictOriginWhenCrossOrigin => "strict-origin-when-cross-origin",
+        }
+        .to_string()
+    }
+}
+
 impl From<ReferrerPolicyHeader> for ReferrerPolicy {
     fn from(policy: ReferrerPolicyHeader) -> Self {
         match policy {

components/script/dom/htmlimageelement.rs

@@ -18,7 +18,7 @@ use crate::dom::bindings::refcounted::Trusted;
 use crate::dom::bindings::reflector::DomObject;
 use crate::dom::bindings::root::{DomRoot, LayoutDom, MutNullableDom};
 use crate::dom::bindings::str::{DOMString, USVString};
-use crate::dom::document::Document;
+use crate::dom::document::{determine_policy_for_token, Document};
 use crate::dom::element::{cors_setting_for_element, referrer_policy_for_element};
 use crate::dom::element::{reflect_cross_origin_attribute, set_cross_origin_attribute};
 use crate::dom::element::{
@@ -1418,6 +1418,21 @@ pub fn parse_a_sizes_attribute(value: DOMString) -> SourceSizeList {
     SourceSizeList::parse(&context, &mut parser)
 }
 
+fn get_correct_referrerpolicy_from_raw_token(token: &DOMString) -> DOMString {
+    if token == "" {
+        // Empty token is treated as no-referrer inside determine_policy_for_token,
+        // while here it should be treated as the default value, so it should remain unchanged.
+        DOMString::new()
+    } else {
+        match determine_policy_for_token(token) {
+            Some(policy) => DOMString::from_string(policy.to_string()),
+            // If the policy is set to an incorrect value, then it should be
+            // treated as an invalid value default (empty string).
+            None => DOMString::new(),
+        }
+    }
+}
+
 impl HTMLImageElementMethods for HTMLImageElement {
     // https://html.spec.whatwg.org/multipage/#dom-img-alt
     make_getter!(Alt, "alt");
@@ -1540,6 +1555,28 @@ impl HTMLImageElementMethods for HTMLImageElement {
         }
     }
 
+    // https://html.spec.whatwg.org/multipage/#dom-img-referrerpolicy
+    fn ReferrerPolicy(&self) -> DOMString {
+        let element = self.upcast::<Element>();
+        let current_policy_value = element.get_string_attribute(&local_name!("referrerpolicy"));
+        get_correct_referrerpolicy_from_raw_token(&current_policy_value)
+    }
+
+    // https://html.spec.whatwg.org/multipage/#dom-img-referrerpolicy
+    fn SetReferrerPolicy(&self, value: DOMString) {
+        let referrerpolicy_attr_name = local_name!("referrerpolicy");
+        let element = self.upcast::<Element>();
+        let previous_correct_attribute_value = get_correct_referrerpolicy_from_raw_token(
+            &element.get_string_attribute(&referrerpolicy_attr_name),
+        );
+        let correct_value_or_empty_string = get_correct_referrerpolicy_from_raw_token(&value);
+        if previous_correct_attribute_value != correct_value_or_empty_string {
+            // Setting the attribute to the same value will update the image.
+            // We don't want to start an update if referrerpolicy is set to the same value.
+            element.set_string_attribute(&referrerpolicy_attr_name, correct_value_or_empty_string);
+        }
+    }
+
     // https://html.spec.whatwg.org/multipage/#dom-img-name
     make_getter!(Name, "name");
 
@@ -1594,7 +1631,8 @@ impl VirtualMethods for HTMLImageElement {
             &local_name!("srcset") |
             &local_name!("width") |
             &local_name!("crossorigin") |
-            &local_name!("sizes") => self.update_the_image_data(),
+            &local_name!("sizes") |
+            &local_name!("referrerpolicy") => self.update_the_image_data(),
             _ => {},
         }
     }

components/script/dom/webidls/HTMLImageElement.webidl

@@ -27,6 +27,8 @@ interface HTMLImageElement : HTMLElement {
   readonly attribute unsigned long naturalHeight;
   readonly attribute boolean complete;
   readonly attribute USVString currentSrc;
+  [CEReactions]
+           attribute DOMString referrerPolicy;
   // also has obsolete members
 };
 

tests/wpt/metadata/custom-elements/reactions/HTMLImageElement.html.ini

@@ -1,10 +1,4 @@
 [HTMLImageElement.html]
-  [referrerPolicy on HTMLImageElement must enqueue an attributeChanged reaction when replacing an existing attribute]
-    expected: FAIL
-
-  [referrerPolicy on HTMLImageElement must enqueue an attributeChanged reaction when adding a new attribute]
-    expected: FAIL
-
   [decoding on HTMLImageElement must enqueue an attributeChanged reaction when replacing an existing attribute]
     expected: FAIL
 

tests/wpt/metadata/html/dom/idlharness.https.html.ini

@@ -2703,9 +2703,6 @@
   [HTMLInputElement interface: createInput("radio") must inherit property "height" with the proper type]
     expected: FAIL
 
-  [HTMLImageElement interface: document.createElement("img") must inherit property "referrerPolicy" with the proper type]
-    expected: FAIL
-
   [HTMLDialogElement interface: operation showModal()]
     expected: FAIL
 
@@ -3045,9 +3042,6 @@
   [HTMLLinkElement interface: document.createElement("link") must inherit property "imageSizes" with the proper type]
     expected: FAIL
 
-  [HTMLImageElement interface: attribute referrerPolicy]
-    expected: FAIL
-
   [HTMLInputElement interface: createInput("time") must inherit property "align" with the proper type]
     expected: FAIL
 
@@ -3276,9 +3270,6 @@
   [HTMLObjectElement interface: attribute width]
     expected: FAIL
 
-  [HTMLImageElement interface: new Image() must inherit property "referrerPolicy" with the proper type]
-    expected: FAIL
-
   [HTMLObjectElement interface: operation getSVGDocument()]
     expected: FAIL
 

tests/wpt/metadata/html/semantics/embedded-content/the-img-element/relevant-mutations.html.ini

@@ -29,40 +29,3 @@
 
   [picture is inserted; img has src]
     expected: FAIL
-
-  [referrerpolicy no-referrer-when-downgrade to empty, src already set]
-    expected: FAIL
-
-  [referrerpolicy no-referrer-when-downgrade to no-referrer, src already set]
-    expected: FAIL
-
-  [referrerpolicy absent to no-referrer-when-downgrade, src already set]
-    expected: FAIL
-
-  [referrerpolicy no-referrer-when-downgrade to absent, src already set]
-    expected: FAIL
-
-  [referrerpolicy no-referrer to invalid, src already set]
-    expected: FAIL
-
-  [referrerpolicy no-referrer to no-referrer-when-downgrade, src already set]
-    expected: FAIL
-
-  [referrerpolicy empty to no-referrer-when-downgrade, src already set]
-    expected: FAIL
-
-  [referrerpolicy no-referrer to empty, src already set]
-    expected: FAIL
-
-  [referrerpolicy absent to no-referrer, src already set]
-    expected: FAIL
-
-  [referrerpolicy no-referrer-when-downgrade to invalid, src already set]
-    expected: FAIL
-
-  [referrerpolicy no-referrer to absent, src already set]
-    expected: FAIL
-
-  [referrerpolicy empty to no-referrer, src already set]
-    expected: FAIL
-