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/BUILD.gn b/sdk/android/BUILD.gn
index bc8e089..83d5f64 100644
--- a/sdk/android/BUILD.gn
+++ b/sdk/android/BUILD.gn
@@ -745,6 +745,7 @@
     "api/org/webrtc/EncodedImage.java",
     "api/org/webrtc/VideoCapturer.java",
     "api/org/webrtc/VideoCodecInfo.java",
+    "api/org/webrtc/CapturerObserver.java",
     "api/org/webrtc/VideoCodecStatus.java",
     "api/org/webrtc/VideoDecoder.java",
     "api/org/webrtc/VideoDecoderFactory.java",
@@ -833,7 +834,6 @@
     "api/org/webrtc/GlRectDrawer.java",
     "api/org/webrtc/VideoDecoderFallback.java",
     "api/org/webrtc/VideoEncoderFallback.java",
-    "src/java/org/webrtc/NativeCapturerObserver.java",
     "src/java/org/webrtc/NV21Buffer.java",
     "src/java/org/webrtc/VideoDecoderWrapper.java",
     "src/java/org/webrtc/VideoEncoderWrapper.java",
@@ -990,6 +990,7 @@
     "api/org/webrtc/VideoSource.java",
     "api/org/webrtc/VideoTrack.java",
     "src/java/org/webrtc/NativeLibrary.java",
+    "src/java/org/webrtc/NativeCapturerObserver.java",
   ]
 
   deps = [