Add VideoEncoder::Settings::numberOfSimulcastStreams.

This helps Java encoders take action if simulcast is enabled or not.

Bug: webrtc:9646
Change-Id: Iad967e237bdc790ff2af111bdec1319f3e661ff7
Reviewed-on: https://webrtc-review.googlesource.com/95651
Reviewed-by: Magnus Jedvert <magjed@webrtc.org>
Commit-Queue: Rasmus Brandt <brandtr@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24430}

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

diff --git a/sdk/android/api/org/webrtc/VideoEncoder.java b/sdk/android/api/org/webrtc/VideoEncoder.java
index b739e99..e1984fa 100644
--- a/sdk/android/api/org/webrtc/VideoEncoder.java
+++ b/sdk/android/api/org/webrtc/VideoEncoder.java
@@ -26,18 +26,26 @@
     public final int height;
     public final int startBitrate; // Kilobits per second.
     public final int maxFramerate;
+    public final int numberOfSimulcastStreams;
     public final boolean automaticResizeOn;
 
     @CalledByNative("Settings")
     public Settings(int numberOfCores, int width, int height, int startBitrate, int maxFramerate,
-        boolean automaticResizeOn) {
+        int numberOfSimulcastStreams, boolean automaticResizeOn) {
       this.numberOfCores = numberOfCores;
       this.width = width;
       this.height = height;
       this.startBitrate = startBitrate;
       this.maxFramerate = maxFramerate;
+      this.numberOfSimulcastStreams = numberOfSimulcastStreams;
       this.automaticResizeOn = automaticResizeOn;
     }
+
+    // TODO(http://bugs.webrtc.org/9646): Remove when downstream clients have been updated.
+    public Settings(int numberOfCores, int width, int height, int startBitrate, int maxFramerate,
+        boolean automaticResizeOn) {
+      this(numberOfCores, width, height, startBitrate, maxFramerate, 1, automaticResizeOn);
+    }
   }
 
   /** Additional info for encoding. */

sdk/android/src/jni/videoencoderwrapper.cc

diff --git a/sdk/android/src/jni/videoencoderwrapper.cc b/sdk/android/src/jni/videoencoderwrapper.cc
index 717f944..ff8be05 100644
--- a/sdk/android/src/jni/videoencoderwrapper.cc
+++ b/sdk/android/src/jni/videoencoderwrapper.cc
@@ -70,7 +70,9 @@
   ScopedJavaLocalRef<jobject> settings = Java_Settings_Constructor(
       jni, number_of_cores_, codec_settings_.width, codec_settings_.height,
       static_cast<int>(codec_settings_.startBitrate),
-      static_cast<int>(codec_settings_.maxFramerate), automatic_resize_on);
+      static_cast<int>(codec_settings_.maxFramerate),
+      static_cast<int>(codec_settings_.numberOfSimulcastStreams),
+      automatic_resize_on);
 
   ScopedJavaLocalRef<jobject> callback =
       Java_VideoEncoderWrapper_createEncoderCallback(jni,