Make sure filters can handle an empty input buffer...

net/base/bzip2_filter.cc

Index: net/base/bzip2_filter.cc
===================================================================
--- net/base/bzip2_filter.cc	(revision 12272)
+++ net/base/bzip2_filter.cc	(working copy)
@@ -56,8 +56,10 @@
     return status;
 
   // Make sure we have valid input data
-  if (!next_stream_data_ || stream_data_len_ <= 0)
-    return status;
+  if (!next_stream_data_ || stream_data_len_ <= 0) {
+    *dest_len = 0;
+    return Filter::FILTER_NEED_MORE_DATA;
+  }
 
   // Fill in bzip2 control block
   int ret, output_len = *dest_len;