Fix use after free in JavascriptAppModalDialogAndroid.

chrome/browser/ui/android/javascript_app_modal_dialog_android.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_ANDROID_JAVASCRIPT_APP_MODAL_DIALOG_ANDROID_H_
 #define CHROME_BROWSER_UI_ANDROID_JAVASCRIPT_APP_MODAL_DIALOG_ANDROID_H_
 
 #include "base/android/jni_helper.h"
 #include "base/android/scoped_java_ref.h"
 #include "base/memory/scoped_ptr.h"
 #include "chrome/browser/ui/app_modal_dialogs/native_app_modal_dialog.h"
 
 class JavaScriptAppModalDialog;
 
 class JavascriptAppModalDialogAndroid : public NativeAppModalDialog {
  public:
   JavascriptAppModalDialogAndroid(JNIEnv* env,
                                   JavaScriptAppModalDialog* dialog,
                                   gfx::NativeWindow parent);
-  virtual ~JavascriptAppModalDialogAndroid();
 
   // NativeAppModalDialog:
   virtual int GetAppModalDialogButtons() const OVERRIDE;
   virtual void ShowAppModalDialog() OVERRIDE;
   virtual void ActivateAppModalDialog() OVERRIDE;
   virtual void CloseAppModalDialog() OVERRIDE;
   virtual void AcceptAppModalDialog() OVERRIDE;
   virtual void CancelAppModalDialog() OVERRIDE;
 
   // Called when java confirms or cancels the dialog.
   void DidAcceptAppModalDialog(JNIEnv* env,
                                jobject obj,
                                jstring prompt_text,
                                bool suppress_js_dialogs);
   void DidCancelAppModalDialog(JNIEnv* env, jobject, bool suppress_js_dialogs);
 
   const base::android::ScopedJavaGlobalRef<jobject>& GetDialogObject() const;
 
   static bool RegisterJavascriptAppModalDialog(JNIEnv* env);
 
  private:
+  // The object deletes itself.
+  virtual ~JavascriptAppModalDialogAndroid();
+
   scoped_ptr<JavaScriptAppModalDialog> dialog_;
   base::android::ScopedJavaGlobalRef<jobject> dialog_jobject_;
   JavaObjectWeakGlobalRef parent_jobject_weak_ref_;
 
   DISALLOW_COPY_AND_ASSIGN(JavascriptAppModalDialogAndroid);
 };
 
 
 #endif  // CHROME_BROWSER_UI_ANDROID_JAVASCRIPT_APP_MODAL_DIALOG_ANDROID_H_