chore: remove unused method Erase() (#43348)

Last use removed in Mar 2018 by 4b39d17e

shell/browser/electron_browser_main_parts.cc

@@ -144,11 +144,6 @@ class LinuxUiGetterImpl : public ui::LinuxUiGetter {
 };
 #endif
 
-template <typename T>
-void Erase(T* container, typename T::iterator iter) {
-  container->erase(iter);
-}
-
 #if BUILDFLAG(IS_WIN)
 int GetMinimumFontSize() {
   int min_font_size;