Remove about:flags#enable-spdy4 flag.

chrome/browser/about_flags.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/about_flags.h"
 
 #include <iterator>
 #include <map>
 #include <set>
 #include <utility>
@@ skipping 791 matching lines @@
   },
   {
     "enable-quic",
     IDS_FLAGS_ENABLE_QUIC_NAME,
     IDS_FLAGS_ENABLE_QUIC_DESCRIPTION,
     kOsAll,
     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableQuic,
                               switches::kDisableQuic)
   },
   {
-    "enable-spdy4",
-    IDS_FLAGS_ENABLE_SPDY4_NAME,
-    IDS_FLAGS_ENABLE_SPDY4_DESCRIPTION,
-    kOsAll,
-    SINGLE_VALUE_TYPE(switches::kEnableSpdy4)
-  },
-  {
     "disable-media-source",
     IDS_FLAGS_DISABLE_MEDIA_SOURCE_NAME,
     IDS_FLAGS_DISABLE_MEDIA_SOURCE_DESCRIPTION,
     kOsAll,
     SINGLE_VALUE_TYPE(switches::kDisableMediaSource)
   },
   {
     "disable-encrypted-media",
     IDS_FLAGS_DISABLE_ENCRYPTED_MEDIA_NAME,
     IDS_FLAGS_DISABLE_ENCRYPTED_MEDIA_DESCRIPTION,
@@ skipping 2228 matching lines @@
 }
 
 const Experiment* GetExperiments(size_t* count) {
   *count = num_experiments;
   return experiments;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags