Notify NativeTheme changed when theme changes

Fix brave/brave-browser#1273

browser/ui/views/frame/brave_browser_frame.cc

@@ -36,4 +36,22 @@ const ui::NativeTheme* BraveBrowserFrame::GetNativeTheme() const {
   // Each platform will implement ui::NativeTheme::GetInstanceForNativeUi
   // separately, which Widget::GetNativeTheme calls.
   return views::Widget::GetNativeTheme();
-}
+}
+
+void BraveBrowserFrame::ThemeChanged() {
+  BrowserFrame::ThemeChanged();
+  // Our native theme values must be changed when our theme is changed
+  // because of white text on white problem for the URLbar and probably
+  // other problems too.
+  // I tried a lot of ways but doing the NotifyObserers here is the only
+  // way that I found which works. Notify Observers does in turn trigger
+  // a call to ThemeChanged though, so to avoid infinite recurison we use
+  // the hack below.
+  static bool inThemeChanged = false;
+  if (!inThemeChanged) {
+    inThemeChanged = true;
+    ui::NativeThemeDarkAura::instance()->NotifyObservers();
+    views::Widget::GetNativeTheme()->NotifyObservers();
+  }
+  inThemeChanged = false;
+}

browser/ui/views/frame/brave_browser_frame.h

@@ -14,6 +14,7 @@ class BraveBrowserFrame : public BrowserFrame {
     explicit BraveBrowserFrame(BrowserView* browser_view);
     ~BraveBrowserFrame() override;
     const ui::NativeTheme* GetNativeTheme() const override;
+    void ThemeChanged() override;
 
   private:
     // The BrowserView is our ClientView. This is a pointer to it.

patches/ui-views-widget-widget.h.patch

@@ -0,0 +1,13 @@
+diff --git a/ui/views/widget/widget.h b/ui/views/widget/widget.h
+index 2efbe5c4d899ec9ec683b6f8ecb058cbe903cd94..d43b471c277a95b3daa245a25d74c2e5624211de 100644
+--- a/ui/views/widget/widget.h
++++ b/ui/views/widget/widget.h
+@@ -637,7 +637,7 @@ class VIEWS_EXPORT Widget : public internal::NativeWidgetDelegate,
+
+   // Notifies the view hierarchy contained in this widget that theme resources
+   // changed.
+-  void ThemeChanged();
++  virtual void ThemeChanged();
+
+   // Notifies the view hierarchy contained in this widget that the device scale
+   // factor changed.