Fold AppModalDialog into its only subclass, JavaScriptAppModalDialog.

chrome/browser/unload_browsertest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if defined(OS_POSIX)
 #include <signal.h>
 #endif
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 177 matching lines @@
     content::WindowedNotificationObserver window_observer(
         chrome::NOTIFICATION_BROWSER_CLOSED,
         content::NotificationService::AllSources());
     chrome::CloseWindow(browser());
     window_observer.Wait();
   }
 
   // If |accept| is true, simulates user clicking OK, otherwise simulates
   // clicking Cancel.
   void ClickModalDialogButton(bool accept) {
-    app_modal::AppModalDialog* dialog = ui_test_utils::WaitForAppModalDialog();
-    ASSERT_TRUE(dialog->IsJavaScriptModalDialog());
-    app_modal::JavaScriptAppModalDialog* js_dialog =
-        static_cast<app_modal::JavaScriptAppModalDialog*>(dialog);
+    app_modal::JavaScriptAppModalDialog* dialog =
+        ui_test_utils::WaitForAppModalDialog();
     if (accept)
-      js_dialog->native_dialog()->AcceptAppModalDialog();
+      dialog->native_dialog()->AcceptAppModalDialog();
     else
-      js_dialog->native_dialog()->CancelAppModalDialog();
+      dialog->native_dialog()->CancelAppModalDialog();
   }
 
   void PrepareForDialog(Browser* browser) {
     for (int i = 0; i < browser->tab_strip_model()->count(); i++) {
       content::PrepContentsForBeforeUnloadTest(
           browser->tab_strip_model()->GetWebContentsAt(i));
     }
   }
 };
 
@@ skipping 711 matching lines @@
       base::Bind(&UnloadResults::AddSuccess, base::Unretained(&unload_results)),
       base::Bind(&UnloadResults::AddAbort, base::Unretained(&unload_results)),
       true);
   window_observer.Wait();
   EXPECT_EQ(1, unload_results.get_successes());
   EXPECT_EQ(0, unload_results.get_aborts());
 }
 
 // TODO(ojan): Add tests for unload/beforeunload that have multiple tabs
 // and multiple windows.