Add history popup when long pressing on the back key.

chrome/browser/ui/android/navigation_popup.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_NAVIGATION_POPUP_H_
+#define CHROME_BROWSER_UI_ANDROID_NAVIGATION_POPUP_H_
+
+#include <jni.h>
+
+#include "base/android/jni_helper.h"
+#include "base/basictypes.h"
+#include "chrome/common/cancelable_task_tracker.h"
+
+class GURL;
+
+namespace history {
+struct FaviconImageResult;
+}
+
+// The native bridge for the history navigation popup that provides additional
+// functionality to the UI widget.
+class NavigationPopup {
+ public:
+  NavigationPopup(JNIEnv* env, jobject obj);
+
+  void Destroy(JNIEnv* env, jobject obj);
+  void FetchFaviconForUrl(JNIEnv* env, jobject obj, jstring jurl);
+
+  void OnFaviconDataAvailable(GURL navigation_entry_url,
+                              const history::FaviconImageResult& image_result);
+
+  static bool RegisterNavigationPopup(JNIEnv* env);
+
+ protected:
+  virtual ~NavigationPopup();
+
+ private:
+  JavaObjectWeakGlobalRef weak_jobject_;
+
+  CancelableTaskTracker cancelable_task_tracker_;
+
+  DISALLOW_COPY_AND_ASSIGN(NavigationPopup);
+};
+
+#endif  // CHROME_BROWSER_UI_ANDROID_NAVIGATION_POPUP_H_