Allow to print Java stack traces in Android camera, renderer and media codec.

talk/app/webrtc/java/src/org/webrtc/MediaCodecVideoDecoder.java

Index: talk/app/webrtc/java/src/org/webrtc/MediaCodecVideoDecoder.java
diff --git a/talk/app/webrtc/java/src/org/webrtc/MediaCodecVideoDecoder.java b/talk/app/webrtc/java/src/org/webrtc/MediaCodecVideoDecoder.java
index 5312fe39a891c8a91a1b92a092fd0f7b7937fe73..f6dcf15b3562d08e85d2735501e2d200c8af026f 100644
--- a/talk/app/webrtc/java/src/org/webrtc/MediaCodecVideoDecoder.java
+++ b/talk/app/webrtc/java/src/org/webrtc/MediaCodecVideoDecoder.java
@@ -32,9 +32,6 @@ import android.media.MediaCodecInfo;
 import android.media.MediaCodecInfo.CodecCapabilities;
 import android.media.MediaCodecList;
 import android.media.MediaFormat;
-import android.opengl.EGLContext;
-import android.opengl.GLES11Ext;
-import android.opengl.GLES20;
 import android.os.Build;
 import android.view.Surface;
 
@@ -65,7 +62,7 @@ public class MediaCodecVideoDecoder {
   }
 
   private static final int DEQUEUE_INPUT_TIMEOUT = 500000;  // 500 ms timeout.
-  private Thread mediaCodecThread;
+  private static Thread mediaCodecThread;
   private MediaCodec mediaCodec;
   private ByteBuffer[] inputBuffers;
   private ByteBuffer[] outputBuffers;
@@ -173,6 +170,18 @@ public class MediaCodecVideoDecoder {
     return findDecoder(H264_MIME_TYPE, supportedH264HwCodecPrefixes) != null;
   }
 
+  public static void printStackTrace() {
+    if (mediaCodecThread != null) {
+      StackTraceElement[] mediaCodecStackTraces = mediaCodecThread.getStackTrace();
+      if (mediaCodecStackTraces.length > 0) {
+        Logging.d(TAG, "MediaCodecVideoDecoder stacks trace:");
+        for (StackTraceElement stackTrace : mediaCodecStackTraces) {
+          Logging.d(TAG, stackTrace.toString());
+        }
+      }
+    }
+  }
+
   private void checkOnMediaCodecThread() throws IllegalStateException {
     if (mediaCodecThread.getId() != Thread.currentThread().getId()) {
       throw new IllegalStateException(