Make the dismiss button on the CF infobar be an image button.

chrome_frame/turndown_prompt/turndown_prompt_window.h

Index: chrome_frame/turndown_prompt/turndown_prompt_window.h
diff --git a/chrome_frame/turndown_prompt/turndown_prompt_window.h b/chrome_frame/turndown_prompt/turndown_prompt_window.h
index 626fca61f58f8a531d43befa629cd2969ba37dc9..695a8500a2f7a028574fdb66d03f352bf4d2553f 100644
--- a/chrome_frame/turndown_prompt/turndown_prompt_window.h
+++ b/chrome_frame/turndown_prompt/turndown_prompt_window.h
@@ -28,8 +28,11 @@ class UrlLauncher;
 
 namespace WTL {
 class CHyperLink;
+class CBitmapButton;
 }  // namespace WTL
 
+class CFBitmapButton;
+
 // Implements a dialog with text and buttons notifying the user that Chrome
 // Frame is being turned down, offering them a link to learn more about moving
 // to a modern browser.
@@ -83,6 +86,10 @@ class TurndownPromptWindow
   // The TurndownPromptWindow manages its own destruction.
   virtual ~TurndownPromptWindow();
 
+  // Performs the necessary configuration to initialize a bitmap button.
+  static void SetupBitmapButton(
+      const base::WeakPtr<TurndownPromptWindow>& window);
+
   // Event handlers.
   void OnDestroy();
   BOOL OnInitDialog(CWindow wndFocus, LPARAM lInitParam);
@@ -101,6 +108,7 @@ class TurndownPromptWindow
 
   InfobarContent::Frame* frame_;  // Not owned by this instance
   scoped_ptr<WTL::CHyperLink> link_;
+  scoped_ptr<CFBitmapButton> close_button_;
   scoped_ptr<UrlLauncher> url_launcher_;
   base::Closure uninstall_closure_;