chrome: win: Fix taskbar grouping of PiP and DevTools windows (fixes #3641)

libcef/browser/chrome/browser_delegate.h

@@ -141,6 +141,10 @@ class BrowserDelegate : public content::WebContentsDelegate {
 
   // Called at the end of a fullscreen transition.
   virtual void WindowFullscreenStateChanged() {}
+
+  // Returns true if this browser has a Views-hosted opener. Only
+  // applicable for Browsers of type picture_in_picture and devtools.
+  virtual bool HasViewsHostedOpener() const { return false; }
 };
 
 }  // namespace cef