Events refactor in Android session based capturing.

webrtc/api/android/java/src/org/webrtc/CameraSession.java

Index: webrtc/api/android/java/src/org/webrtc/CameraSession.java
diff --git a/webrtc/api/android/java/src/org/webrtc/CameraSession.java b/webrtc/api/android/java/src/org/webrtc/CameraSession.java
index c6b73a8bf155dcaaf95ea71dd9f077a78a8446a7..e503547f3e01df994735af5c4db2112494796276 100644
--- a/webrtc/api/android/java/src/org/webrtc/CameraSession.java
+++ b/webrtc/api/android/java/src/org/webrtc/CameraSession.java
@@ -11,11 +11,23 @@
 package org.webrtc;
 
 public interface CameraSession {
+  // Callbacks are fired on the camera thread.
   public interface CreateSessionCallback {
     void onDone(CameraSession session);
     void onFailure(String error);
   }
 
+  // Events are fired on the camera thread.
+  public interface Events {
+    void onCameraError(CameraSession session, String error);
+    void onCameraOpening(CameraSession session);
+    void onCameraClosed(CameraSession session);
+    void onByteBufferFrameCaptured(CameraSession session, byte[] data, int width, int height,
+      int rotation, long timestamp);
+    void onTextureFrameCaptured(CameraSession session, int width, int height, int oesTextureId,
+      float[] transformMatrix, int rotation, long timestamp);
+  }
+
   /**
    * Stops the capture. Waits until no more calls to capture observer will be made.
    * If waitCameraStop is true, also waits for the camera to stop.