Initial work to move downloads to ContentIds

components/offline_items_collection/core/android/java/src/org/chromium/components/offline_items_collection/LegacyHelpers.java

Index: components/offline_items_collection/core/android/java/src/org/chromium/components/offline_items_collection/LegacyHelpers.java
diff --git a/components/offline_items_collection/core/android/java/src/org/chromium/components/offline_items_collection/LegacyHelpers.java b/components/offline_items_collection/core/android/java/src/org/chromium/components/offline_items_collection/LegacyHelpers.java
new file mode 100644
index 0000000000000000000000000000000000000000..e2c797148f4e537260948a9da818ab16260ec18e
--- /dev/null
+++ b/components/offline_items_collection/core/android/java/src/org/chromium/components/offline_items_collection/LegacyHelpers.java
@@ -0,0 +1,53 @@
+// Copyright 2017 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.components.offline_items_collection;
+
+import android.text.TextUtils;
+
+/**
+ * Legacy helper information meant to help with the migration process to OfflineItems.
+ */
+public class LegacyHelpers {
+    // These are legacy namespaces for the purpose of ID generation that will only affect the UI.
+    public static final String LEGACY_DOWNLOAD_NAMESPACE = "LEGACY_DOWNLOAD";
+    public static final String LEGACY_OFFLINE_PAGE_NAMESPACE = "LEGACY_OFFLINE_PAGE";
+
+    /**
+     * Helper to build a {@link ContentId} based on a single GUID for old offline content sources
+     * (downloads and offline pages).
+     * @param isOfflinePage Whether or not {@code guid} is for an offline page or a download.
+     * @param guid          The {@code guid} of the download.
+     * @return              A new {@link ContentId} instance.
+     */
+    public static ContentId buildLegacyContentId(boolean isOfflinePage, String guid) {
+        String namespace =
+                isOfflinePage ? LEGACY_OFFLINE_PAGE_NAMESPACE : LEGACY_DOWNLOAD_NAMESPACE;
+        return new ContentId(namespace, guid);
+    }
+
+    /**
+     * Helper to determine if a {@link ContentId} was created from
+     * {@link #buildLegacyContentId(boolean, String)} for a download ({@code false} for {@code
+     * isOfflinePage}).
+     * @param id The {@link ContentId} to inspect.
+     * @return   Whether or not {@code id} was built for a traditional download.
+     */
+    public static boolean isLegacyDownload(ContentId id) {
+        return TextUtils.equals(LEGACY_DOWNLOAD_NAMESPACE, id.namespace);
+    }
+
+    /**
+     * Helper to determine if a {@link ContentId} was created from
+     * {@link #buildLegacyContentId(boolean, String)} for an offline page ({@code true} for {@code
+     * isOfflinePage}).
+     * @param id The {@link ContentId} to inspect.
+     * @return   Whether or not {@code id} was built for a traditional offline page.
+     */
+    public static boolean isLegacyOfflinePage(ContentId id) {
+        return TextUtils.equals(LEGACY_OFFLINE_PAGE_NAMESPACE, id.namespace);
+    }
+
+    private LegacyHelpers() {}
+}