[Cronet] Upload support for async APIs

components/cronet/android/java/src/org/chromium/net/UploadDataSink.java

+// Copyright 2015 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.net;
+
+/**
+ * Interface with callbacks methods for {@link UploadDataProvider}. All methods
+ * may be called synchronously or asynchronously, on any thread.
+ */
+public interface UploadDataSink {
+    /**
+     * Called by {@link UploadDataProvider} when a read succeeds.
+     * @param finalChunk For chunked uploads, {@code true} if this is the final
+     *     read. It must be {@code false} for non-chunked uploads.
+     */
+    public void onReadSucceeded(boolean finalChunk);
+
+    /**
+     * Called by {@link UploadDataProvider} when a read fails.
+     * @param exception Exception passed on to the embedder.
+     */
+    public void onReadError(Exception exception);
+
+    /**
+     * Called by {@link UploadDataProvider} when a rewind succeeds.
+     */
+    public void onRewindSucceeded();
+
+    /**
+     * Called by {@link UploadDataProvider} when a rewind fails, or if rewinding
+     * uploads is not supported.
+     * @param exception Exception passed on to the embedder.
+     */
+    public void onRewindError(Exception exception);
+}