remove redundant fetch declarations (#691)

Author: saschanaz

baselines/dom.generated.d.ts

@@ -5908,10 +5908,6 @@ interface GlobalEventHandlers {
     removeEventListener(type: string, listener: EventListenerOrEventListenerObject, options?: boolean | EventListenerOptions): void;
 }
 
-interface GlobalFetch {
-    fetch(input: RequestInfo, init?: RequestInit): Promise<Response>;
-}
-
 interface HTMLAllCollection {
     /**
      * Returns the number of elements in the collection.
@@ -17259,7 +17255,7 @@ interface WindowEventMap extends GlobalEventHandlersEventMap, WindowEventHandler
 }
 
 /** A window containing a DOM document; the document property points to the DOM document loaded in that window. */
-interface Window extends EventTarget, WindowTimers, WindowSessionStorage, WindowLocalStorage, WindowConsole, GlobalEventHandlers, IDBEnvironment, WindowBase64, GlobalFetch, WindowOrWorkerGlobalScope, WindowEventHandlers {
+interface Window extends EventTarget, WindowTimers, WindowSessionStorage, WindowLocalStorage, WindowConsole, GlobalEventHandlers, IDBEnvironment, WindowBase64, WindowOrWorkerGlobalScope, WindowEventHandlers {
     Blob: typeof Blob;
     TextDecoder: typeof TextDecoder;
     TextEncoder: typeof TextEncoder;
@@ -18661,7 +18657,6 @@ declare var onwheel: ((this: Window, ev: WheelEvent) => any) | null;
 declare var indexedDB: IDBFactory;
 declare function atob(encodedString: string): string;
 declare function btoa(rawString: string): string;
-declare function fetch(input: RequestInfo, init?: RequestInit): Promise<Response>;
 declare var caches: CacheStorage;
 declare var crypto: Crypto;
 declare var indexedDB: IDBFactory;

baselines/webworker.generated.d.ts

@@ -1617,10 +1617,6 @@ interface GenericTransformStream {
     readonly writable: WritableStream;
 }
 
-interface GlobalFetch {
-    fetch(input: RequestInfo, init?: RequestInit): Promise<Response>;
-}
-
 /** This Fetch API interface allows you to perform various actions on HTTP request and response headers. These actions include retrieving, setting, adding to, and removing. A Headers object has an associated header list, which is initially empty and consists of zero or more name and value pairs.  You can add to this using methods like append() (see Examples.) In all methods of this interface, header names are matched by case-insensitive byte sequence. */
 interface Headers {
     append(name: string, value: string): void;
@@ -4318,7 +4314,7 @@ interface WorkerGlobalScopeEventMap {
 }
 
 /** This Web Workers API interface is an interface representing the scope of any worker. Workers have no browsing context; this scope contains the information usually conveyed by Window objects — in this case event handlers, the console or the associated WorkerNavigator object. Each WorkerGlobalScope has its own event loop. */
-interface WorkerGlobalScope extends EventTarget, WorkerUtils, WindowConsole, GlobalFetch, WindowOrWorkerGlobalScope {
+interface WorkerGlobalScope extends EventTarget, WorkerUtils, WindowConsole, WindowOrWorkerGlobalScope {
     readonly caches: CacheStorage;
     readonly isSecureContext: boolean;
     readonly location: WorkerLocation;
@@ -4722,7 +4718,6 @@ declare function importScripts(...urls: string[]): void;
 declare function atob(encodedString: string): string;
 declare function btoa(rawString: string): string;
 declare var console: Console;
-declare function fetch(input: RequestInfo, init?: RequestInit): Promise<Response>;
 declare var caches: CacheStorage;
 declare var crypto: Crypto;
 declare var indexedDB: IDBFactory;

inputfiles/removedTypes.json

@@ -238,7 +238,10 @@
                         "ontouchmove": null,
                         "ontouchstart": null
                     }
-                }
+                },
+                "implements": [
+                    "GlobalFetch"
+                ]
             },
             "WheelEvent": {
                 "properties": {
@@ -249,6 +252,11 @@
                     }
                 }
             },
+            "WorkerGlobalScope": {
+                "implements": [
+                    "GlobalFetch"
+                ]
+            },
             "XPathEvaluator": {
                 "methods": {
                     "method": {