Bug 1878888 - Add the runtime flag and parsing for the blocking attribute, r=emilio

Differential Revision: https://phabricator.services.mozilla.com/D200810

dom/base/Element.cpp

@@ -276,6 +276,9 @@ nsIFrame* nsIContent::GetPrimaryFrame(mozilla::FlushType aType) {
 
 namespace mozilla::dom {
 
+const DOMTokenListSupportedToken Element::sSupportedBlockingValues[] = {
+    "render", nullptr};
+
 nsDOMAttributeMap* Element::Attributes() {
   nsDOMSlots* slots = DOMSlots();
   if (!slots->mAttributeMap) {

dom/base/Element.h

@@ -1834,6 +1834,11 @@ class Element : public FragmentOrElement {
   static const bool kCallAfterSetAttr = true;
   static const bool kDontCallAfterSetAttr = false;
 
+  /*
+   * The supported values of blocking attribute for use with nsDOMTokenList.
+   */
+  static const DOMTokenListSupportedToken sSupportedBlockingValues[];
+
   /**
    * Set attribute and (if needed) notify documentobservers and fire off
    * mutation events.  This will send the AttributeChanged notification.

dom/html/HTMLLinkElement.cpp

@@ -60,6 +60,7 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(HTMLLinkElement,
   tmp->LinkStyle::Traverse(cb);
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mRelList)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mSizes)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mBlocking)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(HTMLLinkElement,
@@ -67,6 +68,7 @@ NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(HTMLLinkElement,
   tmp->LinkStyle::Unlink();
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mRelList)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mSizes)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mBlocking)
 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
 
 NS_IMPL_ISUPPORTS_CYCLE_COLLECTION_INHERITED_0(HTMLLinkElement,
@@ -693,4 +695,12 @@ bool HTMLLinkElement::IsCSSMimeTypeAttributeForLinkElement(
   return mimeType.IsEmpty() || mimeType.LowerCaseEqualsLiteral("text/css");
 }
 
+nsDOMTokenList* HTMLLinkElement::Blocking() {
+  if (!mBlocking) {
+    mBlocking =
+        new nsDOMTokenList(this, nsGkAtoms::blocking, sSupportedBlockingValues);
+  }
+  return mBlocking;
+}
+
 }  // namespace mozilla::dom

dom/html/HTMLLinkElement.h

@@ -166,6 +166,8 @@ class HTMLLinkElement final : public nsGenericHTMLElement,
     return AttrValueToCORSMode(GetParsedAttr(nsGkAtoms::crossorigin));
   }
 
+  nsDOMTokenList* Blocking();
+
   void NodeInfoChanged(Document* aOldDoc) final {
     mCachedURI = nullptr;
     nsGenericHTMLElement::NodeInfoChanged(aOldDoc);
@@ -197,6 +199,7 @@ class HTMLLinkElement final : public nsGenericHTMLElement,
 
   RefPtr<nsDOMTokenList> mRelList;
   RefPtr<nsDOMTokenList> mSizes;
+  RefPtr<nsDOMTokenList> mBlocking;
 
   // A weak reference to our preload is held only to cancel the preload when
   // this node updates or unbounds from the tree.  We want to prevent cycles,

dom/html/HTMLScriptElement.cpp

@@ -21,6 +21,7 @@
 #include "nsDOMJSUtils.h"
 #include "nsIScriptError.h"
 #include "nsISupportsImpl.h"
+#include "nsDOMTokenList.h"
 #include "mozilla/dom/FetchPriority.h"
 #include "mozilla/dom/HTMLScriptElement.h"
 #include "mozilla/dom/HTMLScriptElementBinding.h"
@@ -47,9 +48,14 @@ HTMLScriptElement::HTMLScriptElement(
 
 HTMLScriptElement::~HTMLScriptElement() = default;
 
-NS_IMPL_ISUPPORTS_INHERITED(HTMLScriptElement, nsGenericHTMLElement,
-                            nsIScriptLoaderObserver, nsIScriptElement,
-                            nsIMutationObserver)
+NS_IMPL_ISUPPORTS_CYCLE_COLLECTION_INHERITED(HTMLScriptElement,
+                                             nsGenericHTMLElement,
+                                             nsIScriptLoaderObserver,
+                                             nsIScriptElement,
+                                             nsIMutationObserver)
+
+NS_IMPL_CYCLE_COLLECTION_INHERITED(HTMLScriptElement, nsGenericHTMLElement,
+                                   mBlocking)
 
 nsresult HTMLScriptElement::BindToTree(BindContext& aContext,
                                        nsINode& aParent) {
@@ -237,4 +243,12 @@ bool HTMLScriptElement::Supports(const GlobalObject& aGlobal,
          aType.EqualsLiteral("importmap");
 }
 
+nsDOMTokenList* HTMLScriptElement::Blocking() {
+  if (!mBlocking) {
+    mBlocking =
+        new nsDOMTokenList(this, nsGkAtoms::blocking, sSupportedBlockingValues);
+  }
+  return mBlocking;
+}
+
 }  // namespace mozilla::dom

dom/html/HTMLScriptElement.h

@@ -13,6 +13,8 @@
 #include "nsGenericHTMLElement.h"
 #include "nsStringFwd.h"
 
+class nsDOMTokenList;
+
 namespace mozilla::dom {
 
 class HTMLScriptElement final : public nsGenericHTMLElement,
@@ -26,6 +28,10 @@ class HTMLScriptElement final : public nsGenericHTMLElement,
   // nsISupports
   NS_DECL_ISUPPORTS_INHERITED
 
+  // CC
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(HTMLScriptElement,
+                                           nsGenericHTMLElement)
+
   void GetInnerHTML(nsAString& aInnerHTML, OOMReporter& aError) override;
   virtual void SetInnerHTML(const nsAString& aInnerHTML,
                             nsIPrincipal* aSubjectPrincipal,
@@ -131,6 +137,8 @@ class HTMLScriptElement final : public nsGenericHTMLElement,
     GetEnumAttr(nsGkAtoms::referrerpolicy, "", aReferrerPolicy);
   }
 
+  nsDOMTokenList* Blocking();
+
   // Required for the webidl-binding because `GetFetchPriority` is overloaded.
   using nsGenericHTMLElement::GetFetchPriority;
 
@@ -150,6 +158,8 @@ class HTMLScriptElement final : public nsGenericHTMLElement,
 
   // ScriptElement
   virtual bool HasScriptContent() override;
+
+  RefPtr<nsDOMTokenList> mBlocking;
 };
 
 }  // namespace mozilla::dom

dom/html/HTMLStyleElement.cpp

@@ -14,6 +14,7 @@
 #include "nsThreadUtils.h"
 #include "nsContentUtils.h"
 #include "nsStubMutationObserver.h"
+#include "nsDOMTokenList.h"
 
 NS_IMPL_NS_NEW_HTML_ELEMENT(Style)
 
@@ -32,11 +33,13 @@ NS_IMPL_CYCLE_COLLECTION_CLASS(HTMLStyleElement)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(HTMLStyleElement,
                                                   nsGenericHTMLElement)
   tmp->LinkStyle::Traverse(cb);
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mBlocking)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(HTMLStyleElement,
                                                 nsGenericHTMLElement)
   tmp->LinkStyle::Unlink();
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mBlocking)
 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
 
 NS_IMPL_ISUPPORTS_CYCLE_COLLECTION_INHERITED(HTMLStyleElement,
@@ -188,4 +191,12 @@ JSObject* HTMLStyleElement::WrapNode(JSContext* aCx,
   return HTMLStyleElement_Binding::Wrap(aCx, this, aGivenProto);
 }
 
+nsDOMTokenList* HTMLStyleElement::Blocking() {
+  if (!mBlocking) {
+    mBlocking =
+        new nsDOMTokenList(this, nsGkAtoms::blocking, sSupportedBlockingValues);
+  }
+  return mBlocking;
+}
+
 }  // namespace mozilla::dom

dom/html/HTMLStyleElement.h

@@ -12,6 +12,8 @@
 #include "nsGenericHTMLElement.h"
 #include "nsStubMutationObserver.h"
 
+class nsDOMTokenList;
+
 namespace mozilla::dom {
 
 class HTMLStyleElement final : public nsGenericHTMLElement,
@@ -71,6 +73,8 @@ class HTMLStyleElement final : public nsGenericHTMLElement,
     SetHTMLAttr(nsGkAtoms::type, aType, aError);
   }
 
+  nsDOMTokenList* Blocking();
+
   virtual JSObject* WrapNode(JSContext* aCx,
                              JS::Handle<JSObject*> aGivenProto) override;
 
@@ -87,6 +91,8 @@ class HTMLStyleElement final : public nsGenericHTMLElement,
    * parent; we should only respond to the change if aContent is non-anonymous.
    */
   void ContentChanged(nsIContent* aContent);
+
+  RefPtr<nsDOMTokenList> mBlocking;
 };
 
 }  // namespace mozilla::dom

dom/webidl/HTMLLinkElement.webidl

@@ -39,6 +39,8 @@ interface HTMLLinkElement : HTMLElement {
            attribute USVString imageSrcset;
   [CEReactions, SetterThrows, Pure]
            attribute USVString imageSizes;
+  [Pref="dom.element.blocking.enabled", SameObject, PutForwards=value]
+           readonly attribute DOMTokenList blocking;
   [Pref="network.fetchpriority.enabled", CEReactions]
            attribute DOMString fetchPriority;
 };

dom/webidl/HTMLScriptElement.webidl

@@ -30,6 +30,8 @@ interface HTMLScriptElement : HTMLElement {
   attribute DOMString referrerPolicy;
   [CEReactions, Throws]
   attribute DOMString text;
+  [Pref="dom.element.blocking.enabled", SameObject, PutForwards=value]
+  readonly attribute DOMTokenList blocking;
   [Pref="network.fetchpriority.enabled", CEReactions]
   attribute DOMString fetchPriority;
 

dom/webidl/HTMLStyleElement.webidl

@@ -18,6 +18,8 @@ interface HTMLStyleElement : HTMLElement {
            attribute DOMString media;
            [CEReactions, SetterThrows, Pure]
            attribute DOMString type;
+           [Pref="dom.element.blocking.enabled", SameObject, PutForwards=value]
+           readonly attribute DOMTokenList blocking;
 };
 HTMLStyleElement includes LinkStyle;
 

modules/libpref/init/StaticPrefList.yaml

@@ -2343,6 +2343,13 @@
   mirror: always
   rust: true
 
+# Whether the blocking attribute implementation is enabled,
+# see https://html.spec.whatwg.org/#blocking-attributes
+- name: dom.element.blocking.enabled
+  type: bool
+  value: false
+  mirror: always
+
 # Whether CustomStateSet is enabled
 - name: dom.element.customstateset.enabled
   type: RelaxedAtomicBool

testing/web-platform/meta/html/dom/render-blocking/__dir__.ini

@@ -0,0 +1 @@
+prefs: [dom.element.blocking.enabled: true]

testing/web-platform/meta/html/dom/render-blocking/blocking-idl-attr.html.ini

@@ -1,18 +0,0 @@
-[blocking-idl-attr.html]
-  [Supported tokens of the 'blocking' IDL attribute of the link element]
-    expected: FAIL
-
-  [Setting the 'blocking' IDL attribute of the link element]
-    expected: FAIL
-
-  [Supported tokens of the 'blocking' IDL attribute of the script element]
-    expected: FAIL
-
-  [Setting the 'blocking' IDL attribute of the script element]
-    expected: FAIL
-
-  [Supported tokens of the 'blocking' IDL attribute of the style element]
-    expected: FAIL
-
-  [Setting the 'blocking' IDL attribute of the style element]
-    expected: FAIL

xpcom/ds/StaticAtoms.py

@@ -189,6 +189,7 @@ STATIC_ATOMS = [
     Atom("black", "black"),
     Atom("block", "block"),
     Atom("block_size", "block-size"),
+    Atom("blocking", "blocking"),
     Atom("blockquote", "blockquote"),
     Atom("blur", "blur"),
     Atom("body", "body"),