Cleanup: Remove unused ui::ResourceBundle::ImageRTL

ui/base/resource/resource_bundle_win.cc

Index: ui/base/resource/resource_bundle_win.cc
diff --git a/ui/base/resource/resource_bundle_win.cc b/ui/base/resource/resource_bundle_win.cc
index 6792870be968c9c0987d2032b453109127230a2b..4546b66fcd7e19ae52ffb216f99b12e1c0f4a316 100644
--- a/ui/base/resource/resource_bundle_win.cc
+++ b/ui/base/resource/resource_bundle_win.cc
@@ -37,10 +37,7 @@ void ResourceBundle::LoadCommonResources() {
   LoadChromeResources();
 }
 
-gfx::Image& ResourceBundle::GetNativeImageNamed(int resource_id, ImageRTL rtl) {
-  // Flipped image is not used on Windows.
-  DCHECK_EQ(rtl, RTL_DISABLED);
-
+gfx::Image& ResourceBundle::GetNativeImageNamed(int resource_id) {
   // Windows only uses SkBitmap for gfx::Image, so this is the same as
   // GetImageNamed.
   return GetImageNamed(resource_id);