Add conditional return type for Clients.matchAll (microsoft#928)

* Add conditional return type for Clients.matchAll

When specifically querying for clients of type window, return the specific WindowClient type.

* Update baselines/webworker.generated.d.ts

Use narrower `extends` test in conditional type.

* Update inputfiles/overridingTypes.json

Add missed source JSON update

Co-authored-by: Nathan Shively-Sanders <[email protected]>

Author: Manduro

baselines/webworker.generated.d.ts

@@ -932,7 +932,7 @@ declare var Client: {
 interface Clients {
     claim(): Promise<void>;
     get(id: string): Promise<Client | undefined>;
-    matchAll(options?: ClientQueryOptions): Promise<ReadonlyArray<Client>>;
+    matchAll<T extends ClientQueryOptions>(options?: T): Promise<ReadonlyArray<T["type"] extends "window" ? WindowClient : Client>>;
     openWindow(url: string): Promise<WindowClient | null>;
 }
 

inputfiles/overridingTypes.json

@@ -2606,6 +2606,11 @@
                             "override-signatures": [
                                 "get(id: string): Promise<Client | undefined>"
                             ]
+                        },
+                        "matchAll": {
+                            "override-signatures": [
+                                "matchAll<T extends ClientQueryOptions>(options?: T): Promise<ReadonlyArray<T[\"type\"] extends \"window\" ? WindowClient : Client>>"
+                            ]
                         }
                     }
                 }