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

ash/system/tray/tray_popup_utils.cc

Index: ash/system/tray/tray_popup_utils.cc
diff --git a/ash/system/tray/tray_popup_utils.cc b/ash/system/tray/tray_popup_utils.cc
index 64fa187d8799c7f3d2df3b985eed1bd28d7ac848..a62d400e57f9651882e7fe68903a89f3f99094b5 100644
--- a/ash/system/tray/tray_popup_utils.cc
+++ b/ash/system/tray/tray_popup_utils.cc
@@ -211,9 +211,8 @@ views::Label* TrayPopupUtils::CreateDefaultLabel() {
   // Frequently the label will paint to a layer that's non-opaque, so subpixel
   // rendering won't work unless we explicitly set a background. See
   // crbug.com/686363
-  label->set_background(
-      views::Background::CreateSolidBackground(kBackgroundColor));
-  label->SetBackgroundColor(kBackgroundColor);
+  label->set_background(views::Background::CreateThemedSolidBackground(
+      label, ui::NativeTheme::kColorId_BubbleBackground));
   return label;
 }
 
@@ -272,8 +271,8 @@ void TrayPopupUtils::ConfigureTrayPopupButton(views::CustomButton* button) {
 
 void TrayPopupUtils::ConfigureAsStickyHeader(views::View* view) {
   view->set_id(VIEW_ID_STICKY_HEADER);
-  view->set_background(
-      views::Background::CreateSolidBackground(kBackgroundColor));
+  view->set_background(views::Background::CreateThemedSolidBackground(
+      view, ui::NativeTheme::kColorId_BubbleBackground));
   view->SetBorder(
       views::CreateEmptyBorder(gfx::Insets(kMenuSeparatorVerticalPadding, 0)));
   view->SetPaintToLayer();