Switch to use download GUID to indentify download items

chrome/android/java/src/org/chromium/chrome/browser/download/DownloadItem.java

Index: chrome/android/java/src/org/chromium/chrome/browser/download/DownloadItem.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadItem.java b/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadItem.java
new file mode 100644
index 0000000000000000000000000000000000000000..1708cb53d436d0a1a52fa289c615f90a5b9e4636
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadItem.java
@@ -0,0 +1,82 @@
+// 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.
+
+package org.chromium.chrome.browser.download;
+
+import org.chromium.content.browser.DownloadInfo;
+
+/**
+ * A generic class representing a download item. The item can be either downloaded through the
+ * Android DownloadManager, or through Chrome's network stack
+ */
+public class DownloadItem {
+    static final long INVALID_DOWNLOAD_ID = -1L;
+    private boolean mUseAndroidDownloadManager;
+    private DownloadInfo mDownloadInfo;
+    private long mDownloadId = INVALID_DOWNLOAD_ID;
+
+    public DownloadItem(boolean useAndroidDownloadManager, DownloadInfo info) {
+        mUseAndroidDownloadManager = useAndroidDownloadManager;
+        mDownloadInfo = info;
+    }
+
+    /**
+     * Sets the system download ID retrieved from Android DownloadManager.
+     *
+     * @param downloadId ID from the Android DownloadManager.
+     */
+    public void setSystemDownloadId(long downloadId) {
+        mDownloadId = downloadId;
+    }
+
+    /**
+     * @return whether the download item has a valid system download ID.
+     */
+    public boolean hasSystemDownloadId() {
+        return mDownloadId != INVALID_DOWNLOAD_ID;
+    }
+
+    /**
+     * @return notification ID for this download.
+     */
+    public int getNotificationId() {
+        if (mUseAndroidDownloadManager) {
+            return (int) mDownloadId;
+        }
+        return mDownloadInfo.getNotificationId();
+    }
+
+    /**
+     * @return System download ID from the Android DownloadManager.
+     */
+    public long getSystemDownloadId() {
+        return mDownloadId;
+    }
+
+    /**
+     * @return String ID that uniquely identifies the download.
+     */
+    public String getId() {
+        if (mUseAndroidDownloadManager) {
+            return String.valueOf(mDownloadId);
+        }
+        return mDownloadInfo.getDownloadGuid();
+    }
+
+    /**
+     * @return Info about the download.
+     */
+    public DownloadInfo getDownloadInfo() {
+        return mDownloadInfo;
+    }
+
+    /**
+     * Sets the system download info.
+     *
+     * @param info Download information.
+     */
+    public void setDownloadInfo(DownloadInfo info) {
+        mDownloadInfo = info;
+    }
+}