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

components/cronet/android/test/javatests/src/org/chromium/net/BidirectionalStreamTest.java

Index: components/cronet/android/test/javatests/src/org/chromium/net/BidirectionalStreamTest.java
diff --git a/components/cronet/android/test/javatests/src/org/chromium/net/BidirectionalStreamTest.java b/components/cronet/android/test/javatests/src/org/chromium/net/BidirectionalStreamTest.java
index 550a6f6ef5386a6850f88b8321de74695d13dc7c..79a2ccdd6e0cc85fc883f503a6569989eed4c413 100644
--- a/components/cronet/android/test/javatests/src/org/chromium/net/BidirectionalStreamTest.java
+++ b/components/cronet/android/test/javatests/src/org/chromium/net/BidirectionalStreamTest.java
@@ -268,6 +268,33 @@ public class BidirectionalStreamTest extends CronetTestBase {
     @SmallTest
     @Feature({"Cronet"})
     @OnlyRunNativeCronet
+    public void testSimplePostWithFlushAfterOneWrite() throws Exception {
+        String url = Http2TestServer.getEchoStreamUrl();
+        TestBidirectionalStreamCallback callback = new TestBidirectionalStreamCallback();
+        callback.addWriteData("Test String".getBytes(), true);
+        BidirectionalStream stream = new BidirectionalStream
+                                             .Builder(url, callback, callback.getExecutor(),
+                                                     mTestFramework.mCronetEngine)
+                                             .disableAutoFlush(true)
+                                             .addHeader("foo", "bar")
+                                             .addHeader("empty", "")
+                                             .addHeader("Content-Type", "zebra")
+                                             .build();
+        stream.start();
+        callback.blockForDone();
+        assertTrue(stream.isDone());
+
+        assertEquals(200, callback.mResponseInfo.getHttpStatusCode());
+        assertEquals("Test String", callback.mResponseAsString);
+        assertEquals("bar", callback.mResponseInfo.getAllHeaders().get("echo-foo").get(0));
+        assertEquals("", callback.mResponseInfo.getAllHeaders().get("echo-empty").get(0));
+        assertEquals(
+                "zebra", callback.mResponseInfo.getAllHeaders().get("echo-content-type").get(0));
+    }
+
+    @SmallTest
+    @Feature({"Cronet"})
+    @OnlyRunNativeCronet
     public void testSimplePostWithFlushTwice() throws Exception {
         String url = Http2TestServer.getEchoStreamUrl();
         TestBidirectionalStreamCallback callback = new TestBidirectionalStreamCallback();