Add VectorIconButton functionality to ImageButton.

ui/views/examples/button_example.h

Index: ui/views/examples/button_example.h
diff --git a/ui/views/examples/button_example.h b/ui/views/examples/button_example.h
index dac61aa3d829d88f2c7a092735a48ac18ff7c235..7869f1fb40611fa95b9479a2e301a140803a7521 100644
--- a/ui/views/examples/button_example.h
+++ b/ui/views/examples/button_example.h
@@ -7,6 +7,7 @@
 
 #include "base/macros.h"
 #include "ui/views/controls/button/button.h"
+#include "ui/views/controls/button/image_button.h"
 #include "ui/views/examples/example_base.h"
 
 namespace views {
@@ -19,7 +20,7 @@ namespace examples {
 
 // ButtonExample simply counts the number of clicks.
 class VIEWS_EXAMPLES_EXPORT ButtonExample : public ExampleBase,
-                                            public ButtonListener {
+                                            public ImageButtonDelegate {
  public:
   ButtonExample();
   ~ButtonExample() override;
@@ -30,7 +31,7 @@ class VIEWS_EXAMPLES_EXPORT ButtonExample : public ExampleBase,
  private:
   void LabelButtonPressed(LabelButton* label_button, const ui::Event& event);
 
-  // ButtonListener:
+  // ImageButtonDelegate:
   void ButtonPressed(Button* sender, const ui::Event& event) override;
 
   // Example buttons.