Bug 802510 - Reset position on the thumbnail data buffer to the beginning before reading out of it. r=blassey a=lsblakk

mobile/android/base/GeckoApp.java

@@ -731,6 +731,7 @@ abstract public class GeckoApp
     void handleThumbnailData(Tab tab, ByteBuffer data) {
         if (shouldUpdateThumbnail(tab)) {
             Bitmap b = tab.getThumbnailBitmap();
+            data.position(0);
             b.copyPixelsFromBuffer(data);
             processThumbnail(tab, b, null);
         }