* Forgot to add

packages/rtl/src/webworkerbase.pas

@@ -0,0 +1,80 @@
+unit webworkerbase;
+
+{$mode ObjFPC}
+{$modeswitch externalclass}
+
+interface
+
+uses
+{$IFDEF FPC_DOTTEDUNITS}
+  JSApi.JS, BrowserApi.WebOrWorker;
+{$ELSE}
+  JS, weborworker;
+{$ENDIF}
+
+Type
+
+  { TJSWorkerNavigator }
+
+  TJSWorkerNavigator = class external name 'WorkerNavigator' (TJSObject)
+  private
+    FhardwareConcurrency: Integer; external name 'hardwareConcurrency';
+    FLanguage: String; external name 'language';
+    FLanguages: TJSStringDynArray; external name 'languages';
+    FOnline: boolean; external name 'onLine';
+    FPlatform: string; external name 'platform';
+    FUserAgent: string; external name 'userAgent';
+  public
+    property language : String read FLanguage;
+    property languages : TJSStringDynArray read FLanguages;
+    property onLine : boolean read FOnline;
+    property platform : string read FPlatform;
+    property userAgent : string read FUserAgent;
+    property hardwareConcurrency : Integer Read FhardwareConcurrency;
+  end;
+
+  { TJSWorkerLocation }
+
+  TJSWorkerLocation = class external name 'WorkerLocation' (TJSObject)
+  Private
+    FHash: string;external name 'hash';
+    FHost: string;external name 'host';
+    FHostName: string;external name 'hostname';
+    FHRef: string; external name 'href';
+    FOrigin : string; external name 'origin';
+    FPathName: string;external name 'pathname';
+    FPort: string;external name 'port';
+    FProtocol: string;external name 'protocol';
+    FSearch: string;external name 'search';
+  Public
+    Property hash : string Read FHash;
+    Property host : string read FHost;
+    Property hostname : string read FHostName;
+    Property href : string read FHRef;
+    Property pathname : string Read FPathName;
+    Property port : string Read FPort;
+    Property protocol : string Read FProtocol;
+    Property search : string read FSearch;
+    property origin : string read FOrigin;
+  end;
+
+  { TJSWorkerGlobalScope }
+
+  TJSWorkerGlobalScope = class external name 'WorkerGlobalScope' (TWindowOrWorkerGlobalScope)
+  private
+    FConsole: TJSConsole; external name 'console';
+    FLocation: TJSWorkerLocation; external name 'location';
+    FNavigator: TJSWorkerNavigator; external name 'navigator';
+    FSelf : TJSWorkerGlobalScope external name 'self';
+  Public
+    procedure importScripts(path : string); varargs;
+    property Navigator: TJSWorkerNavigator read FNavigator;
+    property console : TJSConsole Read FConsole;
+    property location : TJSWorkerLocation Read FLocation;
+    Property Self_ : TJSWorkerGlobalScope Read FSelf;
+  end;
+
+implementation
+
+end.
+