Add VectorIconButton functionality to ImageButton.

chrome/browser/ui/views/ime/ime_window_frame_view.h

Index: chrome/browser/ui/views/ime/ime_window_frame_view.h
diff --git a/chrome/browser/ui/views/ime/ime_window_frame_view.h b/chrome/browser/ui/views/ime/ime_window_frame_view.h
index 1125825de27f5be56a517e878d6cfc983e933726..f55d128d790f146eec13a7b1ddb14222ad047628 100644
--- a/chrome/browser/ui/views/ime/ime_window_frame_view.h
+++ b/chrome/browser/ui/views/ime/ime_window_frame_view.h
@@ -6,11 +6,10 @@
 #define CHROME_BROWSER_UI_VIEWS_IME_IME_WINDOW_FRAME_VIEW_H_
 
 #include "chrome/browser/ui/ime/ime_window.h"
-#include "ui/views/controls/button/button.h"
+#include "ui/views/controls/button/image_button.h"
 #include "ui/views/window/non_client_view.h"
 
 namespace views {
-class ImageButton;
 class ImageView;
 }
 
@@ -20,7 +19,7 @@ class ImeWindowView;
 
 // The non-client frame view implementation for the IME window UI.
 class ImeWindowFrameView : public views::NonClientFrameView,
-                           public views::ButtonListener {
+                           public views::ImageButtonDelegate {
  public:
   // According to the UX spec, the follow-cursor window needs to have the title
   // bar on the side instead of on the top (because the follow-cursor window is