Add option to print peer connection factory Java stack traces.

talk/app/webrtc/java/android/org/webrtc/VideoCapturerAndroid.java

Index: talk/app/webrtc/java/android/org/webrtc/VideoCapturerAndroid.java
diff --git a/talk/app/webrtc/java/android/org/webrtc/VideoCapturerAndroid.java b/talk/app/webrtc/java/android/org/webrtc/VideoCapturerAndroid.java
index ec68ed504d0b370d496edeb5d83e74b3ea56ea9e..27a7d9ba2dd8d0183531de1b9e5f3c2bb0a26be9 100644
--- a/talk/app/webrtc/java/android/org/webrtc/VideoCapturerAndroid.java
+++ b/talk/app/webrtc/java/android/org/webrtc/VideoCapturerAndroid.java
@@ -35,7 +35,6 @@ import android.opengl.EGLContext;
 import android.os.Handler;
 import android.os.HandlerThread;
 import android.os.SystemClock;
-import android.text.StaticLayout;
 import android.view.Surface;
 import android.view.WindowManager;
 
@@ -217,6 +216,18 @@ public class VideoCapturerAndroid extends VideoCapturer implements PreviewCallba
     return capturer;
   }
 
+  public void printStackTrace() {
+    if (cameraThread != null) {
+      StackTraceElement[] cameraStackTraces = cameraThread.getStackTrace();
+      if (cameraStackTraces.length > 0) {
+        Logging.d(TAG, "VideoCapturerAndroid stacks trace:");
+        for (StackTraceElement stackTrace : cameraStackTraces) {
+          Logging.d(TAG, stackTrace.toString());
+        }
+      }
+    }
+  }
+
   // Switch camera to the next valid camera id. This can only be called while
   // the camera is running.
   public void switchCamera(final CameraSwitchHandler handler) {