Update FormData methods to match XMLHttpRequest Standard

Author: NColey

baselines/dom.generated.d.ts

@@ -3796,12 +3796,12 @@ declare var FocusNavigationEvent: {
 }
 
 interface FormData {
-    append(name: any, value: any, fileName?: string): void;
-    delete(name: any): void;
-    get(name: any): any;
-    getAll(name: any): any;
-    has(name: any): any;
-    set(name: any, value: any, fileName?: string): void;
+    append(name: string, value: any, fileName?: string): void;
+    delete(name: string): void;
+    get(name: string): any;
+    getAll(name: string): any[];
+    has(name: string): boolean;
+    set(name: string, value: any, fileName?: string): void;
 }
 
 declare var FormData: {

inputfiles/addedTypes.json

@@ -1540,34 +1540,34 @@
         "interface": "FormData",
         "name": "delete",
         "flavor": "Web",
-        "signatures": ["delete(name: any): void"]
+        "signatures": ["delete(name: string): void"]
     },
     {
         "kind": "method",
         "interface": "FormData",
         "name": "get",
         "flavor": "Web",
-        "signatures": ["get(name: any): any"]
+        "signatures": ["get(name: string): any"]
     },
     {
         "kind": "method",
         "interface": "FormData",
         "name": "getAll",
         "flavor": "Web",
-        "signatures": ["getAll(name: any): any"]
+        "signatures": ["getAll(name: string): any[]"]
     },
     {
         "kind": "method",
         "interface": "FormData",
         "name": "has",
         "flavor": "Web",
-        "signatures": ["has(name: any): any"]
+        "signatures": ["has(name: string): boolean"]
     },
     {
         "kind": "method",
         "interface": "FormData",
         "name": "set",
         "flavor": "Web",
-        "signatures": ["set(name: any, value: any, fileName?: string): void"]
+        "signatures": ["set(name: string, value: any, fileName?: string): void"]
     }
 ]

inputfiles/overridingTypes.json

@@ -1022,6 +1022,6 @@
         "interface": "FormData",
         "name": "append",
         "flavor": "Web",
-        "signatures": ["append(name: any, value: any, fileName?: string): void"]
+        "signatures": ["append(name: string, value: any, fileName?: string): void"]
     }
  ]