Rebase the MessageBubble on the new views bubble.

ui/views/bubble/bubble_delegate.cc

Index: ui/views/bubble/bubble_delegate.cc
diff --git a/ui/views/bubble/bubble_delegate.cc b/ui/views/bubble/bubble_delegate.cc
index 32124b25d7ce5f448e7b790dc7e968e992f07254..66eba038e5f92de22d76e75d2298485d42f96a81 100644
--- a/ui/views/bubble/bubble_delegate.cc
+++ b/ui/views/bubble/bubble_delegate.cc
@@ -71,6 +71,9 @@ Widget* CreateBorderWidget(BubbleDelegateView* bubble, Widget* parent) {
 
 }  // namespace
 
+// TODO(msw): Use NativeTheme/color_helper (crbug.com/105023).
+const SkColor BubbleDelegateView::kBackgroundColor = SK_ColorWHITE;
+
 BubbleDelegateView::BubbleDelegateView()
     : close_on_esc_(true),
       close_on_deactivate_(true),