Add Headers to HeadersInit

Author: mhegazy

baselines/dom.generated.d.ts

@@ -15137,7 +15137,7 @@ type MouseWheelEvent = WheelEvent;
 type ScrollRestoration = "auto" | "manual";
 type FormDataEntryValue = string | File;
 type InsertPosition = "beforebegin" | "afterbegin" | "beforeend" | "afterend";
-type HeadersInit = string[][] | { [key: string]: string };
+type HeadersInit = Headers | string[][] | { [key: string]: string };
 type AppendMode = "segments" | "sequence";
 type AudioContextState = "suspended" | "running" | "closed";
 type BiquadFilterType = "lowpass" | "highpass" | "bandpass" | "lowshelf" | "highshelf" | "peaking" | "notch" | "allpass";
@@ -15208,4 +15208,4 @@ type ServiceWorkerState = "installing" | "installed" | "activating" | "activated
 type Transport = "usb" | "nfc" | "ble";
 type VideoFacingModeEnum = "user" | "environment" | "left" | "right";
 type VisibilityState = "hidden" | "visible" | "prerender" | "unloaded";
-type XMLHttpRequestResponseType = "" | "arraybuffer" | "blob" | "document" | "json" | "text";
+type XMLHttpRequestResponseType = "" | "arraybuffer" | "blob" | "document" | "json" | "text";

baselines/webworker.generated.d.ts

@@ -1890,7 +1890,7 @@ type USVString = string;
 type IDBValidKey = number | string | Date | IDBArrayKey;
 type BufferSource = ArrayBuffer | ArrayBufferView;
 type FormDataEntryValue = string | File;
-type HeadersInit = string[][] | { [key: string]: string };
+type HeadersInit = Headers | string[][] | { [key: string]: string };
 type IDBCursorDirection = "next" | "nextunique" | "prev" | "prevunique";
 type IDBRequestReadyState = "pending" | "done";
 type IDBTransactionMode = "readonly" | "readwrite" | "versionchange";

inputfiles/addedTypes.json

@@ -1934,7 +1934,7 @@
     {
         "kind": "typedef",
         "name": "HeadersInit",
-        "type": "string[][] | { [key: string]: string }"
+        "type": "Headers | string[][] | { [key: string]: string }"
     },
     {
         "kind": "property",