Fix a crash in I420Frame.toString for texture frames.

webrtc/sdk/android/api/org/webrtc/VideoRenderer.java

Index: webrtc/sdk/android/api/org/webrtc/VideoRenderer.java
diff --git a/webrtc/sdk/android/api/org/webrtc/VideoRenderer.java b/webrtc/sdk/android/api/org/webrtc/VideoRenderer.java
index b2812ea8d437fc8bd53de669e8371b004d20d2a5..d247f21821556728e3b17029ad8b5b637e870ac4 100644
--- a/webrtc/sdk/android/api/org/webrtc/VideoRenderer.java
+++ b/webrtc/sdk/android/api/org/webrtc/VideoRenderer.java
@@ -130,7 +130,10 @@ public class VideoRenderer {
 
     @Override
     public String toString() {
-      return width + "x" + height + ":" + yuvStrides[0] + ":" + yuvStrides[1] + ":" + yuvStrides[2];
+      final String type = yuvFrame
+          ? "Y: " + yuvStrides[0] + ", U: " + yuvStrides[1] + ", V: " + yuvStrides[2]
+          : "Texture: " + textureId;
+      return width + "x" + height + ", " + type;
     }
   }