SetStreams API of RtpSender wrapped for iOS and Android

Bug: webrtc:10129
Change-Id: I36ea0110de655bbffa2bd18a024abd15a2136838
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/155983
Commit-Queue: Kári Helgason <kthelgason@webrtc.org>
Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
Reviewed-by: Kári Helgason <kthelgason@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29405}

sdk/android/api/org/webrtc/RtpSender.java

@@ -11,6 +11,7 @@
 package org.webrtc;
 
 import android.support.annotation.Nullable;
+import java.util.List;
 
 /** Java wrapper for a C++ RtpSenderInterface. */
 public class RtpSender {
@@ -62,6 +63,16 @@ public class RtpSender {
     return cachedTrack;
   }
 
+  public void setStreams(List<String> streamIds) {
+    checkRtpSenderExists();
+    nativeSetStreams(nativeRtpSender, streamIds);
+  }
+
+  public List<String> getStreams() {
+    checkRtpSenderExists();
+    return nativeGetStreams(nativeRtpSender);
+  }
+
   public boolean setParameters(RtpParameters parameters) {
     checkRtpSenderExists();
     return nativeSetParameters(nativeRtpSender, parameters);
@@ -117,6 +128,10 @@ public class RtpSender {
   // Will be released in dispose() or setTrack().
   private static native long nativeGetTrack(long rtpSender);
 
+  private static native void nativeSetStreams(long rtpSender, List<String> streamIds);
+
+  private static native List<String> nativeGetStreams(long rtpSender);
+
   // This should increment the reference count of the DTMF sender.
   // Will be released in dispose().
   private static native long nativeGetDtmfSender(long rtpSender);

sdk/android/src/jni/pc/rtp_sender.cc

@@ -45,6 +45,26 @@ jlong JNI_RtpSender_GetTrack(JNIEnv* jni,
           .release());
 }
 
+static void JNI_RtpSender_SetStreams(
+    JNIEnv* jni,
+    jlong j_rtp_sender_pointer,
+    const JavaParamRef<jobject>& j_stream_labels) {
+  reinterpret_cast<RtpSenderInterface*>(j_rtp_sender_pointer)
+      ->SetStreams(JavaListToNativeVector<std::string, jstring>(
+          jni, j_stream_labels, &JavaToNativeString));
+}
+
+ScopedJavaLocalRef<jobject> JNI_RtpSender_GetStreams(
+    JNIEnv* jni,
+    jlong j_rtp_sender_pointer) {
+  ScopedJavaLocalRef<jstring> (*convert_function)(JNIEnv*, const std::string&) =
+      &NativeToJavaString;
+  return NativeToJavaList(
+      jni,
+      reinterpret_cast<RtpSenderInterface*>(j_rtp_sender_pointer)->stream_ids(),
+      convert_function);
+}
+
 jlong JNI_RtpSender_GetDtmfSender(JNIEnv* jni,
                                   jlong j_rtp_sender_pointer) {
   return jlongFromPointer(