Add signal to request (#39290)

The signal taken from the requestinit is now passed into
the request object with the relevant steps. I added all
spec comments to this method, as I had trouble figuring
out which steps I had to add.

This required implementing the algorithm to create
dependent signals, which is used in the `any()` method.
So that's now implemented as well.

All of that required the machinery to have dependent and
source signals on an AbortSignal. It uses an IndexSet
as the spec requires it to be an ordered set.

Part of #34866

Signed-off-by: Tim van der Lippe <tvanderlippe@gmail.com>

components/script_bindings/codegen/Bindings.conf

@@ -20,7 +20,7 @@ DOMInterfaces = {
 },
 
 'AbortSignal': {
-    'canGc':['Abort'],
+    'canGc':['Abort', 'Any'],
 },
 
 'AbstractRange': {

components/script_bindings/webidls/AbortSignal.webidl

@@ -7,6 +7,8 @@
 [Exposed=*, Pref="dom_abort_controller_enabled"]
 interface AbortSignal : EventTarget {
   [NewObject] static AbortSignal abort(optional any reason);
+  // [Exposed=(Window,Worker), NewObject] static AbortSignal timeout([EnforceRange] unsigned long long milliseconds);
+  [NewObject] static AbortSignal _any(sequence<AbortSignal> signals);
   readonly attribute boolean aborted;
   readonly attribute any reason;
   undefined throwIfAborted();

components/script_bindings/webidls/Request.webidl

@@ -6,6 +6,7 @@
 
 typedef (Request or USVString) RequestInfo;
 
+// https://fetch.spec.whatwg.org/#request
 [Exposed=(Window,Worker)]
 interface Request {
   [Throws] constructor(RequestInfo input, optional RequestInit init = {});
@@ -21,12 +22,18 @@ interface Request {
   readonly attribute RequestCache cache;
   readonly attribute RequestRedirect redirect;
   readonly attribute DOMString integrity;
+  // readonly attribute boolean keepalive;
+  // readonly attribute boolean isReloadNavigation;
+  // readonly attribute boolean isHistoryNavigation;
+  readonly attribute AbortSignal signal;
+  // readonly attribute RequestDuplex duplex;
 
   [NewObject, Throws] Request clone();
 };
 
 Request includes Body;
 
+// https://fetch.spec.whatwg.org/#requestinit
 dictionary RequestInit {
   ByteString method;
   HeadersInit headers;
@@ -38,9 +45,14 @@ dictionary RequestInit {
   RequestCache cache;
   RequestRedirect redirect;
   DOMString integrity;
+  // boolean keepalive;
+  AbortSignal? signal;
+  // RequestDuplex duplex;
+  // RequestPriority priority;
   any window; // can only be set to null
 };
 
+// https://fetch.spec.whatwg.org/#requestdestination
 enum RequestDestination {
   "",
   "audio",
@@ -63,6 +75,7 @@ enum RequestDestination {
   "xslt"
 };
 
+// https://fetch.spec.whatwg.org/#requestmode
 enum RequestMode {
   "navigate",
   "same-origin",
@@ -70,12 +83,14 @@ enum RequestMode {
   "cors"
 };
 
+// https://fetch.spec.whatwg.org/#requestcredentials
 enum RequestCredentials {
   "omit",
   "same-origin",
   "include"
 };
 
+// https://fetch.spec.whatwg.org/#requestcache
 enum RequestCache {
   "default",
   "no-store",
@@ -85,12 +100,14 @@ enum RequestCache {
   "only-if-cached"
 };
 
+// https://fetch.spec.whatwg.org/#requestredirect
 enum RequestRedirect {
   "follow",
   "error",
   "manual"
 };
 
+// https://w3c.github.io/webappsec-referrer-policy/#enumdef-referrerpolicy
 enum ReferrerPolicy {
   "",
   "no-referrer",