🔧 Enable mode indication for setProgressBar

This commit enables setting a mode for the setProgressBar method.
Old behavior is kept intact, usage is entirely optional.

atom/browser/ui/win/taskbar_host.h

@@ -35,7 +35,7 @@ class TaskbarHost {
       HWND window, const std::vector<ThumbarButton>& buttons);
 
   // Set the progress state in taskbar.
-  bool SetProgressBar(HWND window, double value);
+  bool SetProgressBar(HWND window, double value, const std::string& mode);
 
   // Set the overlay icon in taskbar.
   bool SetOverlayIcon(