Upstream changes to HttpUrlRequest for querying response headers and closing ReadableByteChannel.

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

 // Copyright 2014 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;
 
 import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.nio.channels.ReadableByteChannel;
 
@@ skipping 40 matching lines @@
      * @param contentType MIME type of the post content or null if this is not a
      *            POST.
      * @param data The content that needs to be uploaded if this is a POST
      *            request.
      */
     void setUploadData(String contentType, byte[] data);
 
     /**
      * Sets a readable byte channel to upload as part of a POST request.
      *
+     * <p>Once {@link #start()} is called, this channel is guaranteed to be
+     * closed, either when the upload completes, or when it is canceled.
+     *
      * @param contentType MIME type of the post content or null if this is not a
      *            POST.
      * @param channel The channel to read to read upload data from if this is a
      *            POST request.
      */
     void setUploadChannel(String contentType, ReadableByteChannel channel);
 
     /**
      * Start executing the request.
      * <p>
@@ skipping 35 matching lines @@
 
     /**
      * Returns the HTTP status code. It may be 0 if the request has not started
      * or failed before getting the status code from the server. If the status
      * code is 206 (partial response) after {@link #setOffset} is called, the
      * method returns 200.
      */
     int getHttpStatusCode();
 
     /**
+     * Returns the response header value for the given name or {@code null} if
+     * not found.
+     */
+    String getHeader(String name);
+
+
+    /**
      * Returns the exception that occurred while executing the request of null
      * if the request was successful.
      */
     IOException getException();
 }