procedure TForm1.ActiveControlChanged(Sender: TObject);  
begin  
 Memo1.Lines.Add('ActiveControlChanged:'+ActiveControl.Name);  
end;  

procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);  
begin  
 Screen.OnActiveControlChange := nil;  
end;  
procedure TForm1.FormCreate(Sender: TObject);  
begin  
 Screen.OnActiveControlChange := ActiveControlChanged;  
end;  

 if IsChildWindow(Chromium1, GetFocus) then
   SetFocusedControl(Chromium1);

function IsChildWindow(AParent: TWinControl; AChildHandle: HWND): Boolean;

 function InternalNativeIsChildWindow(AParent: TWinControl): Boolean;
 begin
   Result := IsChild(NativeHandle(AParent.Handle), AChildHandle);
 end;

 function InternalIsChildWindow(AParent: TWinControl): Boolean;
 var
   I: Integer;
   APopupWindow: TcxCustomPopupWindow;
 begin
   with AParent do
     for I := 0 to ControlCount - 1 do
       if Controls[I] is TWinControl then
       begin
         if HasNativeHandle(TWinControl(Controls[I]), AChildHandle) then
         begin
           Result := True;
           Exit;
         end else
         begin
           Result := InternalIsChildWindow(TWinControl(Controls[I]));
           if Result then
             Exit;
         end;
         Result := InternalNativeIsChildWindow(TWinControl(Controls[I]));
         if Result then
           Exit;
       end;
   if AParent is TcxCustomPopupWindow then
     for I := 0 to FVisiblePopupWindowList.Count - 1 do
     begin
       APopupWindow := TcxCustomPopupWindow(FVisiblePopupWindowList[I]);
       if (APopupWindow = AParent) or (GetParentForm(APopupWindow.OwnerControl) <> AParent) then
         Continue;
       if HasNativeHandle(APopupWindow, AChildHandle) then
       begin
         Result := True;
         Exit;
       end else
       begin
         Result := InternalIsChildWindow(APopupWindow);
         if Result then Exit;
       end;
     end;
   for I := 0 to FVisiblePopupWindowList.Count - 1 do
   begin
     APopupWindow := TcxCustomPopupWindow(FVisiblePopupWindowList[I]);
     if APopupWindow.OwnerControl = AParent then
     begin
       Result := HasNativeHandle(APopupWindow, AChildHandle) or
         InternalIsChildWindow(APopupWindow);
       if Result then Exit;
     end;
   end;
   Result := False;
 end;

begin
 Result := False;
 if (AParent = nil) or (AChildHandle = 0) or HasNativeHandle(AParent, AChildHandle) then
   Exit;
 Result := InternalNativeIsChildWindow(AParent);
 if not Result then
   Result := InternalIsChildWindow(AParent);
end;