VideoCapturerAndroid: Check if data is null in onPreviewFrame()

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

Index: talk/app/webrtc/java/src/org/webrtc/VideoCapturerAndroid.java
diff --git a/talk/app/webrtc/java/src/org/webrtc/VideoCapturerAndroid.java b/talk/app/webrtc/java/src/org/webrtc/VideoCapturerAndroid.java
index d1e45701b3f7dc0da7835287e5c235a449e780d9..25ed3f7b76f007c3fea5ba7975a7acc382d74858 100644
--- a/talk/app/webrtc/java/src/org/webrtc/VideoCapturerAndroid.java
+++ b/talk/app/webrtc/java/src/org/webrtc/VideoCapturerAndroid.java
@@ -910,7 +910,7 @@ public class VideoCapturerAndroid extends VideoCapturer implements PreviewCallba
         // Frames might be posted to |onPreviewFrame| with the previous format while changing
         // capture format in |startPreviewOnCameraThread|. Drop these old frames.
         Log.w(TAG, "Received callback buffer from previous configuration with length: "
-            + data.length);
+            + (data == null ? "null" : data.length));
         return false;
       }
       if (buffer.capacity() != frameSize) {