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

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

Index: talk/app/webrtc/java/android/org/webrtc/VideoRendererGui.java
diff --git a/talk/app/webrtc/java/android/org/webrtc/VideoRendererGui.java b/talk/app/webrtc/java/android/org/webrtc/VideoRendererGui.java
index afaebf6f2eea1072c5671f3564ecb578615abe4d..1d413b8ece89d1a42cb6a7a89b6c371f9784c1d2 100644
--- a/talk/app/webrtc/java/android/org/webrtc/VideoRendererGui.java
+++ b/talk/app/webrtc/java/android/org/webrtc/VideoRendererGui.java
@@ -36,12 +36,10 @@ import javax.microedition.khronos.opengles.GL10;
 import android.annotation.SuppressLint;
 import android.graphics.Point;
 import android.graphics.Rect;
-import android.graphics.SurfaceTexture;
 import android.opengl.EGL14;
 import android.opengl.EGLContext;
 import android.opengl.GLES20;
 import android.opengl.GLSurfaceView;
-import android.opengl.Matrix;
 
 import org.webrtc.Logging;
 import org.webrtc.VideoRenderer.I420Frame;
@@ -77,6 +75,9 @@ public class VideoRendererGui implements GLSurfaceView.Renderer {
   // Current SDK version.
   private static final int CURRENT_SDK_VERSION =
       android.os.Build.VERSION.SDK_INT;
+  // Render and draw threads.
+  private static Thread renderFrameThread;
+  private static Thread drawThread;
 
   private VideoRendererGui(GLSurfaceView surface) {
     this.surface = surface;
@@ -372,6 +373,9 @@ public class VideoRendererGui implements GLSurfaceView.Renderer {
         VideoRenderer.renderFrameDone(frame);
         return;
       }
+      if (renderFrameThread == null) {
+        renderFrameThread = Thread.currentThread();
+      }
       if (!seenFrame && rendererEvents != null) {
         Logging.d(TAG, "ID: " + id + ". Reporting first rendered frame.");
         rendererEvents.onFirstFrameRendered();
@@ -394,6 +398,7 @@ public class VideoRendererGui implements GLSurfaceView.Renderer {
           // Skip rendering of this frame if previous frame was not rendered yet.
           framesDropped++;
           VideoRenderer.renderFrameDone(frame);
+          seenFrame = true;
           return;
         }
         pendingFrame = frame;
@@ -430,6 +435,8 @@ public class VideoRendererGui implements GLSurfaceView.Renderer {
       }
       instance.yuvImageRenderers.clear();
     }
+    renderFrameThread = null;
+    drawThread = null;
     instance.surface = null;
     eglContext = null;
     eglContextReady = null;
@@ -565,6 +572,26 @@ public class VideoRendererGui implements GLSurfaceView.Renderer {
     }
   }
 
+  private static void printStackTrace(Thread thread, String threadName) {
+    if (thread != null) {
+      StackTraceElement[] stackTraces = thread.getStackTrace();
+      if (stackTraces.length > 0) {
+        Logging.d(TAG, threadName + " stacks trace:");
+        for (StackTraceElement stackTrace : stackTraces) {
+          Logging.d(TAG, stackTrace.toString());
+        }
+      }
+    }
+  }
+
+  public static synchronized void printStackTraces() {
+    if (instance == null) {
+      return;
+    }
+    printStackTrace(renderFrameThread, "Render frame thread");
+    printStackTrace(drawThread, "Draw thread");
+  }
+
   @SuppressLint("NewApi")
   @Override
   public void onSurfaceCreated(GL10 unused, EGLConfig config) {
@@ -613,6 +640,9 @@ public class VideoRendererGui implements GLSurfaceView.Renderer {
 
   @Override
   public void onDrawFrame(GL10 unused) {
+    if (drawThread == null) {
+      drawThread = Thread.currentThread();
+    }
     GLES20.glViewport(0, 0, screenWidth, screenHeight);
     GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
     synchronized (yuvImageRenderers) {