Support for video file instead of camera and output video out to file

webrtc/api/BUILD.gn

Index: webrtc/api/BUILD.gn
diff --git a/webrtc/api/BUILD.gn b/webrtc/api/BUILD.gn
index cae9e65d4e0af9d0ce2c9eaa2e4c64bafc0ca372..aeb3501f7befde8496bc8ee225b2d86207cdcf7f 100644
--- a/webrtc/api/BUILD.gn
+++ b/webrtc/api/BUILD.gn
@@ -258,8 +258,11 @@ if (is_android && !build_with_chromium) {
       "android/java/src/org/webrtc/EglBase.java",
       "android/java/src/org/webrtc/EglBase10.java",
       "android/java/src/org/webrtc/EglBase14.java",
+      "android/java/src/org/webrtc/FileVideoCapturer.java",
+      "android/java/src/org/webrtc/FileVideoCapturerTimer.java",
       "android/java/src/org/webrtc/GlRectDrawer.java",
       "android/java/src/org/webrtc/GlShader.java",
+      "android/java/src/org/webrtc/GlVideoFileRenderer.java",
       "android/java/src/org/webrtc/GlTextureFrameBuffer.java",
       "android/java/src/org/webrtc/GlUtil.java",
       "android/java/src/org/webrtc/IceCandidate.java",