Add Android Camera To Unity Plugin

webrtc/examples/unityplugin/unity_plugin_apis.h

 /*
  *  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.
  */
 
@@ skipping 19 matching lines @@
 typedef void (*LOCALSDPREADYTOSEND_CALLBACK)(const char* type, const char* sdp);
 typedef void (*ICECANDIDATEREADYTOSEND_CALLBACK)(const char* candidate,
                                                  const int sdp_mline_index,
                                                  const char* sdp_mid);
 typedef void (*AUDIOBUSREADY_CALLBACK)(const void* audio_data,
                                        int bits_per_sample,
                                        int sample_rate,
                                        int number_of_channels,
                                        int number_of_frames);
 
+#if defined(WEBRTC_WIN)
 #define WEBRTC_PLUGIN_API __declspec(dllexport)
+#elif defined(WEBRTC_ANDROID)
+#define WEBRTC_PLUGIN_API __attribute__((visibility("default")))
+#endif
 extern "C" {
 // Create a peerconnection and return a unique peer connection id.
 WEBRTC_PLUGIN_API int CreatePeerConnection(const char** turn_urls,
                                            const int no_of_urls,
                                            const char* username,
                                            const char* credential);
 // Close a peerconnection.
 WEBRTC_PLUGIN_API bool ClosePeerConnection(int peer_connection_id);
 // Add a audio stream. If audio_only is true, the stream only has an audio
 // track and no video track.
@@ skipping 41 matching lines @@
                                                AUDIOBUSREADY_CALLBACK callback);
 WEBRTC_PLUGIN_API bool RegisterOnLocalSdpReadytoSend(
     int peer_connection_id,
     LOCALSDPREADYTOSEND_CALLBACK callback);
 WEBRTC_PLUGIN_API bool RegisterOnIceCandiateReadytoSend(
     int peer_connection_id,
     ICECANDIDATEREADYTOSEND_CALLBACK callback);
 }
 
 #endif  // WEBRTC_EXAMPLES_UNITYPLUGIN_UNITY_PLUGIN_APIS_H_