Fix clang, and clean up apple-specific code

src/frontend/helpers/dpi_aware_dialog.cpp

@@ -36,12 +36,12 @@ void DPIAwareDialog::showEvent(QShowEvent* event) {
 #endif
 }
 
+#ifndef __APPLE__
 void DPIAwareDialog::resizeEvent(QResizeEvent* event) {
     QDialog::resizeEvent(event);
     resized = true;
 }
 
-#ifndef __APPLE__
 void DPIAwareDialog::OnScreenChanged() {
     // Resize according to DPI
     const double scaleX = window_handle->screen()->logicalDotsPerInchX() / 96.0;

src/frontend/helpers/dpi_aware_dialog.h

@@ -13,24 +13,27 @@ public:
 
 protected:
     void showEvent(QShowEvent* event) override;
-    void resizeEvent(QResizeEvent* event) override;
 
     // Called with two zeroes to set up content sizes that are relative to dialog size. Also called
     // when screen is changed, to update those sizes.
     virtual void SetContentSizes(int previous_width = 0, int previous_height = 0){};
 
 private:
-#ifndef __APPLE__
-    void OnScreenChanged();
-#endif
-
     QWindow* window_handle{};
     const int original_width{};
     const int original_height{};
 
+#ifndef __APPLE__
+protected:
+    void resizeEvent(QResizeEvent* event) override;
+
+private:
+    void OnScreenChanged();
+
     bool resized = false; // whether this dialog has been manually resized
     double previous_scaleX{};
     double previous_scaleY{};
     int previous_width{};
     int previous_height{};
+#endif
 };