Android: Add video processing interface

This CL adds an API for injecting video processing after the WebRTC
CPU and QP scaling step.

Bug: webrtc:10247
Change-Id: I776498e1e9113f50e953ee411bbb31f181863312
Reviewed-on: https://webrtc-review.googlesource.com/c/119953
Commit-Queue: Magnus Jedvert <magjed@webrtc.org>
Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26740}
diff --git a/sdk/android/BUILD.gn b/sdk/android/BUILD.gn
index cbae015..01acfc5 100644
--- a/sdk/android/BUILD.gn
+++ b/sdk/android/BUILD.gn
@@ -326,6 +326,7 @@
       "api/org/webrtc/StatsReport.java",
       "api/org/webrtc/TurnCustomizer.java",
       "api/org/webrtc/VideoSource.java",
+      "api/org/webrtc/VideoProcessor.java",
       "api/org/webrtc/VideoTrack.java",
       "src/java/org/webrtc/NativeLibrary.java",
       "src/java/org/webrtc/NativeCapturerObserver.java",