Remove dart:codec and move classes into dart:convert.

runtime/vm/symbols.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_SYMBOLS_H_
 #define VM_SYMBOLS_H_
 
 #include "vm/object.h"
 #include "vm/snapshot_ids.h"
 
@@ skipping 235 matching lines @@
   V(_as, "_as")                                                                \
   V(GetterPrefix, "get:")                                                      \
   V(SetterPrefix, "set:")                                                      \
   V(PrivateGetterPrefix, "get:_")                                              \
   V(PrivateSetterPrefix, "set:_")                                              \
   V(_New, "_new")                                                              \
   V(DartScheme, "dart:")                                                       \
   V(DartSchemePrivate, "dart:_")                                               \
   V(DartNativeWrappers, "dart:nativewrappers")                                 \
   V(DartAsync, "dart:async")                                                   \
-  V(DartCodec, "dart:codec")                                                   \
   V(DartCore, "dart:core")                                                     \
   V(DartCollection, "dart:collection")                                         \
   V(DartCollectionDev, "dart:_collection-dev")                                 \
   V(DartConvert, "dart:convert")                                               \
   V(DartIsolate, "dart:isolate")                                               \
   V(DartJson, "dart:json")                                                     \
   V(DartMath, "dart:math")                                                     \
   V(DartMirrors, "dart:mirrors")                                               \
   V(DartTypedData, "dart:typed_data")                                          \
   V(DartUtf, "dart:utf")                                                       \
@@ skipping 199 matching lines @@
   friend class SnapshotReader;
   friend class SnapshotWriter;
   friend class ApiMessageReader;
 
   DISALLOW_COPY_AND_ASSIGN(Symbols);
 };
 
 }  // namespace dart
 
 #endif  // VM_SYMBOLS_H_