Refactor AppModalDialogQueue and move JS Alert boxes into a MVC.

chrome/browser/jsmessage_box_handler.h

Index: chrome/browser/jsmessage_box_handler.h
diff --git a/chrome/browser/jsmessage_box_handler.h b/chrome/browser/jsmessage_box_handler.h
index 149bfd7cabec044721d9ed5da27300dab267715e..86e7b70732b26139707e15cb2dcfac5f17e005f1 100644
--- a/chrome/browser/jsmessage_box_handler.h
+++ b/chrome/browser/jsmessage_box_handler.h
@@ -26,4 +26,12 @@ void RunJavascriptMessageBox(WebContents* web_contents,
                              bool display_suppress_checkbox,
                              IPC::Message* reply_msg);
 
+// This will display a modal dialog box with a header and footer asking the
+// the user if they wish to navigate away from a page, with additional text
+// |message_text| between the header and footer. The users response is
+// returned to the renderer using |reply_msg|.
+void RunBeforeUnloadDialog(WebContents* web_contents,
+                           const std::wstring& message_text,
+                           IPC::Message* reply_msg);
+
 #endif // CHROME_BROWSER_JSMESSAGE_BOX_HANDLER_H_