athena: Make sure the window captions update correctly for theme-color.

athena/activity/activity_frame_view.cc

Index: athena/activity/activity_frame_view.cc
diff --git a/athena/activity/activity_frame_view.cc b/athena/activity/activity_frame_view.cc
index 08aeb3d12fa6d651143d9389015a22162ee6e550..83b93885b5fcc64482e0c51d0bd3b55de8482d8d 100644
--- a/athena/activity/activity_frame_view.cc
+++ b/athena/activity/activity_frame_view.cc
@@ -72,15 +72,18 @@ void ActivityFrameView::ResetWindowControls() {
 }
 
 void ActivityFrameView::UpdateWindowIcon() {
-}
-
-void ActivityFrameView::UpdateWindowTitle() {
   if (!view_model_->UsesFrame())
     return;
 
   SkColor bgcolor = view_model_->GetRepresentativeColor();
-  title_->set_background(views::Background::CreateSolidBackground(bgcolor));
+  set_background(views::Background::CreateSolidBackground(bgcolor));
   title_->SetBackgroundColor(bgcolor);
+  SchedulePaint();
+}
+
+void ActivityFrameView::UpdateWindowTitle() {
+  if (!view_model_->UsesFrame())
+    return;
   title_->SetText(frame_->widget_delegate()->GetWindowTitle());
 }