Implement deleteItem and openItem on OfflinePageDownloadBridge.

chrome/browser/android/offline_pages/downloads/offline_page_download_bridge.h

 // Copyright 2016 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_ANDROID_OFFLINE_PAGES_DOWNLOADS_OFFLINE_PAGE_DOWNLOAD_BRIDGE_H_
 #define CHROME_BROWSER_ANDROID_OFFLINE_PAGES_DOWNLOADS_OFFLINE_PAGE_DOWNLOAD_BRIDGE_H_
 
 #include <stdint.h>
 
 #include "base/android/jni_android.h"
@@ skipping 26 matching lines @@
 
   void GetAllItems(JNIEnv* env,
                    const base::android::JavaParamRef<jobject>& obj,
                    const base::android::JavaParamRef<jobject>& j_result_obj);
 
   base::android::ScopedJavaLocalRef<jobject> GetItemByGuid(
       JNIEnv* env,
       const base::android::JavaParamRef<jobject>& obj,
       const base::android::JavaParamRef<jstring>& j_guid);
 
+  void DeleteItemByGuid(JNIEnv* env,
+                        const base::android::JavaParamRef<jobject>& obj,
+                        const base::android::JavaParamRef<jstring>& j_guid);
+
+  base::android::ScopedJavaLocalRef<jstring> GetOfflineUrlByGuid(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj,
+      const base::android::JavaParamRef<jstring>& j_guid);
+
   // DownloadUIAdapter::Observer implementation.
   void ItemsLoaded() override;
   void ItemAdded(const DownloadUIItem& item) override;
   void ItemUpdated(const DownloadUIItem& item) override;
   void ItemDeleted(const std::string& guid) override;
 
  private:
   JavaObjectWeakGlobalRef weak_java_ref_;
 
   // Not owned.
   DownloadUIAdapter* download_ui_adapter_;
 
   DISALLOW_COPY_AND_ASSIGN(OfflinePageDownloadBridge);
 };
 
 }  // namespace android
 }  // namespace offline_pages
 
 #endif  // CHROME_BROWSER_ANDROID_OFFLINE_PAGES_DOWNLOADS_OFFLINE_PAGE_DOWNLOAD_BRIDGE_H_