[Cronet] Make delaying sending request headers explicit in bidirectional stream

components/cronet/android/api/src/org/chromium/net/CronetEngine.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;
 
 import android.content.Context;
 import android.net.http.HttpResponseCache;
 import android.support.annotation.IntDef;
 import android.support.annotation.Nullable;
@@ skipping 693 matching lines @@
      *
      * @param url the URL for the stream
      * @param callback the object whose methods get invoked upon different events
      * @param executor the {@link Executor} on which all callbacks will be called
      * @param httpMethod the HTTP method to use for the stream
      * @param requestHeaders the list of request headers
      * @param priority priority of the stream which should be one of the
      *         {@link BidirectionalStream.Builder#STREAM_PRIORITY_IDLE STREAM_PRIORITY_*}
      *         values.
      * @param disableAutoFlush whether auto flush should be disabled
+     * @param delayRequestHeadersUntilFirstFlush whether to delay sending request
+     *         headers until flush() is called, and try to combine them
+     *         with the next data frame.
      * @return a new stream.
      */
     abstract BidirectionalStream createBidirectionalStream(String url,
             BidirectionalStream.Callback callback, Executor executor, String httpMethod,
             List<Map.Entry<String, String>> requestHeaders,
-            @BidirectionalStream.Builder.StreamPriority int priority, boolean disableAutoFlush);
+            @BidirectionalStream.Builder.StreamPriority int priority, boolean disableAutoFlush,
+            boolean delayRequestHeadersUntilFirstFlush);
 
     /**
      * @return {@code true} if the engine is enabled.
      */
     abstract boolean isEnabled();
 
     /**
      * @return a human-readable version string of the engine.
      */
     public abstract String getVersionString();
@@ skipping 374 matching lines @@
      * @hide as it's a prototype.
      */
     public interface RequestFinishedListener { // TODO(klm): Add a convenience abstract class.
         /**
          * Invoked with request info.
          * @param requestInfo {@link UrlRequestInfo} for finished request.
          */
         void onRequestFinished(UrlRequestInfo requestInfo);
     }
 }