Add support for adding VideoSinks to VideoTracks.

webrtc/sdk/android/src/jni/wrapped_native_i420_buffer.cc

 /*
  *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #include "webrtc/sdk/android/src/jni/wrapped_native_i420_buffer.h"
 
 #include "webrtc/sdk/android/src/jni/classreferenceholder.h"
 #include "webrtc/sdk/android/src/jni/jni_helpers.h"
 
 namespace webrtc_jni {
 
 // TODO(magjed): Write a test for this function.
 jobject WrapI420Buffer(
+    JNIEnv* jni,
     const rtc::scoped_refptr<webrtc::I420BufferInterface>& i420_buffer) {
-  JNIEnv* jni = AttachCurrentThreadIfNeeded();
-  ScopedLocalRefFrame local_ref_frame(jni);
-
   jclass j_wrapped_native_i420_buffer_class =
       FindClass(jni, "org/webrtc/WrappedNativeI420Buffer");
   jmethodID j_wrapped_native_i420_buffer_ctor_id =
       GetMethodID(jni, j_wrapped_native_i420_buffer_class, "<init>",
                   "(IILjava/nio/ByteBuffer;ILjava/nio/ByteBuffer;ILjava/nio/"
                   "ByteBuffer;IJ)V");
 
   jobject y_buffer =
       jni->NewDirectByteBuffer(const_cast<uint8_t*>(i420_buffer->DataY()),
                                i420_buffer->StrideY() * i420_buffer->height());
@@ skipping 18 matching lines @@
 (JNIEnv* jni, jclass, jlong j_buffer_pointer) {
   reinterpret_cast<webrtc::VideoFrameBuffer*>(j_buffer_pointer)->AddRef();
 }
 
 JOW(void, WrappedNativeI420Buffer_nativeRelease)
 (JNIEnv* jni, jclass, jlong j_buffer_pointer) {
   reinterpret_cast<webrtc::VideoFrameBuffer*>(j_buffer_pointer)->Release();
 }
 
 }  // namespace webrtc_jni