Deprecate PeerConnectionFactory#createVideoSource(VideoCapturer).

This is done in preparation of moving VideoCapturer out of
video_api_java. Clients should update to using
createVideoSource(boolean).

CapturerObserver is moved to a separate file because it needs to stay
in video_api_java to allow VideoSource to depend on it.

Bug: webrtc:9496
Change-Id: I3c93f6bc4df553919dcbe05b00ef4c68f2c9ab60
Reviewed-on: https://webrtc-review.googlesource.com/87305
Reviewed-by: Magnus Jedvert <magjed@webrtc.org>
Commit-Queue: Sami Kalliomäki <sakal@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23868}
diff --git a/sdk/android/api/org/webrtc/VideoSource.java b/sdk/android/api/org/webrtc/VideoSource.java
index 3a290e3..fb0ad1a 100644
--- a/sdk/android/api/org/webrtc/VideoSource.java
+++ b/sdk/android/api/org/webrtc/VideoSource.java
@@ -40,7 +40,7 @@
     nativeAdaptOutputFormat(nativeSource, width, height, fps);
   }
 
-  public VideoCapturer.CapturerObserver getCapturerObserver() {
+  public CapturerObserver getCapturerObserver() {
     return capturerObserver;
   }