PeerConnection.java: enable setting trace & log levels from Java

Replaces the hard-coded scheme that was there before and lets apps decide what
to log and to where.

R=wu@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/1969004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@4498 4adac7df-926f-26a2-2b94-8c16560cd09d

talk/examples/android/src/org/appspot/apprtc/AppRTCDemoActivity.java

@@ -44,6 +44,7 @@ import org.json.JSONException;
 import org.json.JSONObject;
 import org.webrtc.DataChannel;
 import org.webrtc.IceCandidate;
+import org.webrtc.Logging;
 import org.webrtc.MediaConstraints;
 import org.webrtc.MediaStream;
 import org.webrtc.PeerConnection;
@@ -58,6 +59,7 @@ import org.webrtc.VideoRenderer.I420Frame;
 import org.webrtc.VideoSource;
 import org.webrtc.VideoTrack;
 
+import java.util.EnumSet;
 import java.util.LinkedList;
 import java.util.List;
 
@@ -98,6 +100,12 @@ public class AppRTCDemoActivity extends Activity
           }
         });
 
+    // Uncomment to get ALL WebRTC tracing and SENSITIVE libjingle logging.
+    // Logging.enableTracing(
+    //     "/sdcard/trace.txt",
+    //     EnumSet.of(Logging.TraceLevel.TRACE_ALL),
+    //     Logging.Severity.LS_SENSITIVE);
+
     PowerManager powerManager = (PowerManager) getSystemService(POWER_SERVICE);
     wakeLock = powerManager.newWakeLock(
         PowerManager.SCREEN_BRIGHT_WAKE_LOCK, "AppRTCDemo");