[Views] Add a capability to the bubble delegate to be able to show the title in BaseFont.

ui/views/bubble/bubble_delegate.h

Index: ui/views/bubble/bubble_delegate.h
diff --git a/ui/views/bubble/bubble_delegate.h b/ui/views/bubble/bubble_delegate.h
index b3d299997f0808da40685a283483443a5701c674..e61111b096df70d8ed677d77113bfc9b88819708 100644
--- a/ui/views/bubble/bubble_delegate.h
+++ b/ui/views/bubble/bubble_delegate.h
@@ -12,6 +12,7 @@
 #include "ui/views/widget/widget_observer.h"
 
 namespace gfx {
+class FontList;
 class Rect;
 }
 
@@ -117,6 +118,10 @@ class VIEWS_EXPORT BubbleDelegateView : public WidgetDelegateView,
   // Get bubble bounds from the anchor rect and client view's preferred size.
   virtual gfx::Rect GetBubbleBounds();
 
+  // Return a FontList to use for the title of the bubble.
+  // (The default is MediumFont).
+  virtual const gfx::FontList& GetTitleFontList() const;
+
   // View overrides:
   virtual bool AcceleratorPressed(const ui::Accelerator& accelerator) OVERRIDE;
   virtual void OnNativeThemeChanged(const ui::NativeTheme* theme) OVERRIDE;