lint / remove vestigial func

shell/browser/api/electron_api_desktop_capturer.cc

@@ -265,16 +265,6 @@ void DesktopCapturer::DesktopListListener::OnSourceRemoved() {
   std::move(update_callback_).Run();
 }
 
-void DesktopCapturer::DesktopListListener::OnThumbnailRefresh() {
-    if (have_selection_) {
-      have_selection_ = false;
-
-      std::move(update_callback_).Run();
-  } else {
-    have_thumbnail_ = true;
-  }
-}
-
 void DesktopCapturer::DesktopListListener::OnDelegatedSourceListDismissed() {
   std::move(failure_callback_).Run();
 }

shell/browser/api/electron_api_desktop_capturer.h

@@ -64,7 +64,6 @@ class DesktopCapturer final : public gin::Wrappable<DesktopCapturer>,
   void OnSourceMoved(int old_index, int new_index) override {}
   void OnSourceNameChanged(int index) override {}
   void OnSourceThumbnailChanged(int index) override {}
-  void OnThumbnailRefresh() override {}
   void OnSourcePreviewChanged(size_t index) override {}
   void OnDelegatedSourceListSelection() override {}
   void OnDelegatedSourceListDismissed() override {}