Update from https://crrev.com/304715

net/filter/filter.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // Filter performs filtering on data streams. Sample usage:
 //
 //   IStream* pre_filter_source;
 //   ...
 //   Filter* filter = Filter::Factory(filter_type, size);
 //   int pre_filter_data_len = filter->stream_buffer_size();
@@ skipping 207 matching lines @@
   // Given a array of encoding_types, try to do some error recovery adjustment
   // to the list.  This includes handling known bugs in the Apache server (where
   // redundant gzip encoding is specified), as well as issues regarding SDCH
   // encoding, where various proxies and anti-virus products modify or strip the
   // encodings.  These fixups require context, which includes whether this
   // response was made to an SDCH request (i.e., an available dictionary was
   // advertised in the GET), as well as the mime type of the content.
   static void FixupEncodingTypes(const FilterContext& filter_context,
                                  std::vector<FilterType>* encoding_types);
 
+  // Returns a string describing the FilterTypes implemented by this filter.
+  std::string OrderedFilterList() const;
+
  protected:
   friend class GZipUnitTest;
   friend class SdchFilterChainingTest;
   FRIEND_TEST_ALL_PREFIXES(FilterTest, ThreeFilterChain);
 
-  Filter();
+  explicit Filter(FilterType type_id);
 
   // Filters the data stored in stream_buffer_ and writes the output into the
   // dest_buffer passed in.
   //
   // Upon entry, *dest_len is the total size (in number of chars) of the
   // destination buffer. Upon exit, *dest_len is the actual number of chars
   // written into the destination buffer.
   //
   // This function will fail if there is no pre-filter data in the
   // stream_buffer_. On the other hand, *dest_len can be 0 upon successful
@@ skipping 43 matching lines @@
   void PushDataIntoNextFilter();
 
   // Constructs a filter with an internal buffer of the given size.
   // Only meant to be called by unit tests that need to control the buffer size.
   static Filter* FactoryForTests(const std::vector<FilterType>& filter_types,
                                  const FilterContext& filter_context,
                                  int buffer_size);
 
   // An optional filter to process output from this filter.
   scoped_ptr<Filter> next_filter_;
+
   // Remember what status or local filter last returned so we can better handle
   // chained filters.
   FilterStatus last_status_;
 
+  // The filter type this filter was constructed from.
+  FilterType type_id_;
+
   DISALLOW_COPY_AND_ASSIGN(Filter);
 };
 
 }  // namespace net
 
 #endif  // NET_FILTER_FILTER_H__