Adding Java wrapper for DtmfSender.

webrtc/sdk/android/instrumentationtests/src/org/webrtc/PeerConnectionTest.java

Index: webrtc/sdk/android/instrumentationtests/src/org/webrtc/PeerConnectionTest.java
diff --git a/webrtc/sdk/android/instrumentationtests/src/org/webrtc/PeerConnectionTest.java b/webrtc/sdk/android/instrumentationtests/src/org/webrtc/PeerConnectionTest.java
index 418b9337f1e11b5de81dcec25144b59577927d8c..8849edd2da1f1ceb97ad849bb5f7d08d66eb6e62 100644
--- a/webrtc/sdk/android/instrumentationtests/src/org/webrtc/PeerConnectionTest.java
+++ b/webrtc/sdk/android/instrumentationtests/src/org/webrtc/PeerConnectionTest.java
@@ -716,14 +716,20 @@ public class PeerConnectionTest {
     assertEquals(PeerConnection.SignalingState.STABLE, offeringPC.signalingState());
     assertEquals(PeerConnection.SignalingState.STABLE, answeringPC.signalingState());
 
-    // Set a bitrate limit for the outgoing video stream for the offerer.
+    // Test some of the RtpSender API.
     RtpSender videoSender = null;
+    RtpSender audioSender = null;
     for (RtpSender sender : offeringPC.getSenders()) {
       if (sender.track().kind().equals("video")) {
         videoSender = sender;
+      } else {
+        audioSender = sender;
       }
     }
     assertNotNull(videoSender);
+    assertNotNull(audioSender);
+
+    // Set a bitrate limit for the outgoing video stream for the offerer.
     RtpParameters rtpParameters = videoSender.getParameters();
     assertNotNull(rtpParameters);
     assertEquals(1, rtpParameters.encodings.size());
@@ -732,6 +738,12 @@ public class PeerConnectionTest {
     rtpParameters.encodings.get(0).maxBitrateBps = 300000;
     assertTrue(videoSender.setParameters(rtpParameters));
 
+    // Create a DTMF sender.
+    DtmfSender dtmfSender = audioSender.dtmf();
+    assertNotNull(dtmfSender);
+    assertTrue(dtmfSender.canInsertDtmf());
+    assertTrue(dtmfSender.insertDtmf("123", 300, 100));
+
     // Verify that we can read back the updated value.
     rtpParameters = videoSender.getParameters();
     assertEquals(300000, (int) rtpParameters.encodings.get(0).maxBitrateBps);