Initial work to move downloads to ContentIds

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
index 7c98a936264607b5c3e4c7a041786519db25a3fd..f21ca94e1a41422c643534f45be137617380f681 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadItem.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadItem.java
@@ -5,6 +5,7 @@
 package org.chromium.chrome.browser.download;
 
 import org.chromium.base.annotations.CalledByNative;
+import org.chromium.components.offline_items_collection.ContentId;
 
 /**
  * A generic class representing a download item. The item can be either downloaded through the
@@ -17,6 +18,7 @@ public class DownloadItem {
     public static final int INDETERMINATE_DOWNLOAD_PERCENTAGE = -1;
     static final long INVALID_DOWNLOAD_ID = -1L;
 
+    private final ContentId mContentId = new ContentId();
     private boolean mUseAndroidDownloadManager;
     private DownloadInfo mDownloadInfo;
     private long mDownloadId = INVALID_DOWNLOAD_ID;
@@ -26,6 +28,8 @@ public class DownloadItem {
     public DownloadItem(boolean useAndroidDownloadManager, DownloadInfo info) {
         mUseAndroidDownloadManager = useAndroidDownloadManager;
         mDownloadInfo = info;
+        if (mDownloadInfo != null) mContentId.namespace = mDownloadInfo.getContentId().namespace;
+        mContentId.id = getId();
     }
 
     /**
@@ -35,6 +39,9 @@ public class DownloadItem {
      */
     public void setSystemDownloadId(long downloadId) {
         mDownloadId = downloadId;
+
+        // Update our ContentId in case it changed.
+        mContentId.id = getId();
     }
 
     /**
@@ -52,6 +59,14 @@ public class DownloadItem {
     }
 
     /**
+     * @return A {@link ContentId} that represents this downloaded item.  The id will match
+     *         {@link #getId()}.
+     */
+    public ContentId getContentId() {
+        return mContentId;
+    }
+
+    /**
      * @return String ID that uniquely identifies the download.
      */
     public String getId() {