Introduce a type of View background that stays in sync with its host

ui/views/background.h

Index: ui/views/background.h
diff --git a/ui/views/background.h b/ui/views/background.h
index 6648689d56447dd54e564b810177a4c302a49d41..81bb675a37feb3fd00a2ada9e58b132001489cf9 100644
--- a/ui/views/background.h
+++ b/ui/views/background.h
@@ -12,6 +12,7 @@
 #include "base/macros.h"
 #include "build/build_config.h"
 #include "third_party/skia/include/core/SkColor.h"
+#include "ui/native_theme/native_theme.h"
 #include "ui/views/views_export.h"
 
 #if defined(OS_WIN)
@@ -47,6 +48,12 @@ class VIEWS_EXPORT Background {
   // Creates a background that fills the canvas in the specified color.
   static Background* CreateSolidBackground(SkColor color);
 
+  // Creates a background that fills the canvas in the color specified by the
+  // view's NativeTheme and the given color identifier.
+  static Background* CreateThemedSolidBackground(
+      View* view,
+      ui::NativeTheme::ColorId color_id);
+
   // Creates a background that fills the canvas in the specified color.
   static Background* CreateSolidBackground(int r, int g, int b) {
     return CreateSolidBackground(SkColorSetRGB(r, g, b));