Introduce BubbleDialogDelegateView, which extends DialogDelegateView

ui/views/examples/widget_example.cc

Index: ui/views/examples/widget_example.cc
diff --git a/ui/views/examples/widget_example.cc b/ui/views/examples/widget_example.cc
index bcfb451aa85bdb180042d35641e8d8c4b8e4cb2c..0165de3f9dcb8805b70ce4a1860ed741be5a1e14 100644
--- a/ui/views/examples/widget_example.cc
+++ b/ui/views/examples/widget_example.cc
@@ -28,7 +28,6 @@ class DialogExample : public DialogDelegateView {
   ~DialogExample() override;
   base::string16 GetWindowTitle() const override;
   View* CreateExtraView() override;
-  View* CreateTitlebarExtraView() override;
   View* CreateFootnoteView() override;
 };
 
@@ -61,12 +60,6 @@ View* DialogExample::CreateExtraView() {
   return button;
 }
 
-View* DialogExample::CreateTitlebarExtraView() {
-  Label* label = new Label(ASCIIToUTF16("Extra view!"));
-  label->SetEnabledColor(SK_ColorBLUE);
-  return label;
-}
-
 View* DialogExample::CreateFootnoteView() {
   return new Label(ASCIIToUTF16("Footnote label!"));
 }