Use filter context to track stats better in SDCH filtering

net/base/sdch_filter_unittest.cc

Index: net/base/sdch_filter_unittest.cc
===================================================================
--- net/base/sdch_filter_unittest.cc	(revision 11636)
+++ net/base/sdch_filter_unittest.cc	(working copy)
@@ -747,11 +747,14 @@
   // System should automatically add the missing (optional) gzip.
   std::vector<Filter::FilterType> filter_types;
   filter_types.push_back(Filter::FILTER_TYPE_SDCH);
-  Filter::FixupEncodingTypes(true, "anything/mime", &filter_types);
 
-  // First try with a large buffer (larger than test input, or compressed data).
   const int kInputBufferSize(100);
   MockFilterContext filter_context(kInputBufferSize);
+  filter_context.SetMimeType("anything/mime");
+  filter_context.SetSdchResponse(true);
+  Filter::FixupEncodingTypes(filter_context, &filter_types);
+
+  // First try with a large buffer (larger than test input, or compressed data).
   filter_context.SetURL(url);
   scoped_ptr<Filter> filter(Filter::Factory(filter_types, filter_context));