Avoid meta-refresh when back-button gets non-sdch content...

net/base/sdch_manager.h

 // Copyright (c) 2006-2008 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.
 
 // Provides global database of differential decompression dictionaries for the
 // SDCH filter (processes sdch enconded content).
 
 // Exactly one instance of SdchManager is built, and all references are made
 // into that collection.
 //
@@ skipping 106 matching lines @@
     META_REFRESH_RECOVERY = 70,            // Dictionary not found.
     // defunct =  71, // Almost the same as META_REFRESH_UNSUPPORTED.
     // defunct = 72,  // Almost the same as CACHED_META_REFRESH_UNSUPPORTED.
     // defunct = 73,  // PASSING_THROUGH_NON_SDCH plus DISCARD_TENTATIVE_SDCH.
     META_REFRESH_UNSUPPORTED = 74,         // Unrecoverable error.
     CACHED_META_REFRESH_UNSUPPORTED = 75,  // As above, but pulled from cache.
     PASSING_THROUGH_NON_SDCH = 76,  // Non-html tagged as sdch but malformed.
     INCOMPLETE_SDCH_CONTENT = 77,   // Last window was not completely decoded.
     PASS_THROUGH_404_CODE = 78,     // URL not found message passing through.
 
+    // This next report is very common, and not really an error scenario, but
+    // it exercises the error recovery logic.
+    PASS_THROUGH_OLD_CACHED = 79,   // Back button got pre-SDCH cached content.
+
     // Common decoded recovery methods.
     META_REFRESH_CACHED_RECOVERY = 80,  // Probably startup tab loading.
     DISCARD_TENTATIVE_SDCH = 81,        // Server decided not to use sdch.
 
     // Non SDCH problems, only accounted for to make stat counting complete
     // (i.e., be able to be sure all dictionary advertisements are accounted
     // for).
 
     UNFLUSHED_CONTENT = 90,    // Possible error in filter chaining.
     // defunct = 91,           // MISSING_TIME_STATS (Should never happen.)
@@ skipping 217 matching lines @@
   DomainCounter exponential_blacklist_count;
 
   // List of hostnames for which a latency experiment is allowed (because a
   // round trip test has recently passed).
   ExperimentSet allow_latency_experiment_;
 
   DISALLOW_COPY_AND_ASSIGN(SdchManager);
 };
 
 #endif  // NET_BASE_SDCH_MANAGER_H_