PeerConnection(java): Add OnRenegotiationNeeded support

Also:
- Make PeerConnectionObserver::OnRenegotiationNeeded() pure virtual to avoid
  this sort of mistake in the future.
- Sprinkle @Override annotations on some callback definitions that were missing
  them.
- Fix a JNI method-signature-lookup typo (s/(V)V/()V/) in PCOJava::OnError()
- Add an explicit ScopedLocalFrameRef to PCOJava::OnError() to match all other
  C++-fired callbacks, for consistency.

BUG=2771
R=wu@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/6829004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@5376 4adac7df-926f-26a2-2b94-8c16560cd09d

talk/app/webrtc/java/jni/peerconnection_jni.cc

@@ -515,7 +515,8 @@ class PCOJava : public PeerConnectionObserver {
   }
 
   virtual void OnError() OVERRIDE {
-    jmethodID m = GetMethodID(jni(), *j_observer_class_, "onError", "(V)V");
+    ScopedLocalRefFrame local_ref_frame(jni());
+    jmethodID m = GetMethodID(jni(), *j_observer_class_, "onError", "()V");
     jni()->CallVoidMethod(*j_observer_global_, m);
     CHECK_EXCEPTION(jni(), "error during CallVoidMethod");
   }
@@ -648,6 +649,14 @@ class PCOJava : public PeerConnectionObserver {
     CHECK_EXCEPTION(jni(), "error during CallVoidMethod");
   }
 
+  virtual void OnRenegotiationNeeded() OVERRIDE {
+    ScopedLocalRefFrame local_ref_frame(jni());
+    jmethodID m =
+        GetMethodID(jni(), *j_observer_class_, "onRenegotiationNeeded", "()V");
+    jni()->CallVoidMethod(*j_observer_global_, m);
+    CHECK_EXCEPTION(jni(), "error during CallVoidMethod");
+  }
+
   void SetConstraints(ConstraintsWrapper* constraints) {
     CHECK(!constraints_.get(), "constraints already set!");
     constraints_.reset(constraints);

talk/app/webrtc/java/src/org/webrtc/PeerConnection.java

@@ -82,6 +82,9 @@ public class PeerConnection {
 
     /** Triggered when a remote peer opens a DataChannel. */
     public void onDataChannel(DataChannel dataChannel);
+
+    /** Triggered when renegotiation is necessary. */
+    public void onRenegotiationNeeded();
   }
 
   /** Java version of PeerConnectionInterface.IceServer. */

talk/app/webrtc/javatests/src/org/webrtc/PeerConnectionTest.java

@@ -59,6 +59,7 @@ public class PeerConnectionTest extends TestCase {
     private final String name;
     private int expectedIceCandidates = 0;
     private int expectedErrors = 0;
+    private int expectedRenegotiations = 0;
     private int expectedSetSize = 0;
     private int previouslySeenWidth = 0;
     private int previouslySeenHeight = 0;
@@ -103,6 +104,7 @@ public class PeerConnectionTest extends TestCase {
       expectedIceCandidates += count;
     }
 
+    @Override
     public synchronized void onIceCandidate(IceCandidate candidate) {
       --expectedIceCandidates;
       // We don't assert expectedIceCandidates >= 0 because it's hard to know
@@ -115,6 +117,7 @@ public class PeerConnectionTest extends TestCase {
       ++expectedErrors;
     }
 
+    @Override
     public synchronized void onError() {
       assertTrue(--expectedErrors >= 0);
     }
@@ -236,6 +239,15 @@ public class PeerConnectionTest extends TestCase {
       assertEquals(DataChannel.State.CONNECTING, dataChannel.state());
     }
 
+    public synchronized void expectRenegotiationNeeded() {
+      ++expectedRenegotiations;
+    }
+
+    @Override
+    public synchronized void onRenegotiationNeeded() {
+      assertTrue(--expectedRenegotiations >= 0);
+    }
+
     public synchronized void expectMessage(ByteBuffer expectedBuffer,
                                            boolean expectedBinary) {
       expectedBuffers.add(
@@ -375,20 +387,24 @@ public class PeerConnectionTest extends TestCase {
 
     public SdpObserverLatch() {}
 
+    @Override
     public void onCreateSuccess(SessionDescription sdp) {
       this.sdp = sdp;
       onSetSuccess();
     }
 
+    @Override
     public void onSetSuccess() {
       success = true;
       latch.countDown();
     }
 
+    @Override
     public void onCreateFailure(String error) {
       onSetFailure(error);
     }
 
+    @Override
     public void onSetFailure(String error) {
       this.error = error;
       latch.countDown();
@@ -529,10 +545,12 @@ public class PeerConnectionTest extends TestCase {
     // Drop |label| params from {Audio,Video}Track-related APIs once
     // https://code.google.com/p/webrtc/issues/detail?id=1253 is fixed.
     offeringExpectations.expectSetSize();
+    offeringExpectations.expectRenegotiationNeeded();
     WeakReference<MediaStream> oLMS = addTracksToPC(
         factory, offeringPC, videoSource, "oLMS", "oLMSv0", "oLMSa0",
         offeringExpectations);
 
+    offeringExpectations.expectRenegotiationNeeded();
     DataChannel offeringDC = offeringPC.createDataChannel(
         "offeringDC", new DataChannel.Init());
     assertEquals("offeringDC", offeringDC.label());
@@ -557,6 +575,7 @@ public class PeerConnectionTest extends TestCase {
     assertNull(sdpLatch.getSdp());
 
     answeringExpectations.expectSetSize();
+    answeringExpectations.expectRenegotiationNeeded();
     WeakReference<MediaStream> aLMS = addTracksToPC(
         factory, answeringPC, videoSource, "aLMS", "aLMSv0", "aLMSa0",
         answeringExpectations);

talk/app/webrtc/peerconnectioninterface.h

@@ -277,7 +277,7 @@ class PeerConnectionObserver {
   virtual void OnDataChannel(DataChannelInterface* data_channel) {}
 
   // Triggered when renegotation is needed, for example the ICE has restarted.
-  virtual void OnRenegotiationNeeded() {}
+  virtual void OnRenegotiationNeeded() = 0;
 
   // Called any time the IceConnectionState changes
   virtual void OnIceConnectionChange(

talk/examples/android/src/org/appspot/apprtc/AppRTCDemoActivity.java

@@ -419,6 +419,11 @@ public class AppRTCDemoActivity extends Activity
           }
         });
     }
+
+    @Override public void onRenegotiationNeeded() {
+      // No need to do anything; AppRTC follows a pre-agreed-upon
+      // signaling/negotiation protocol.
+    }
   }
 
   // Implementation detail: handle offer creation/signaling and answer setting,