Remove dart:platform library.

runtime/vm/object.cc

 // 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.
 
 #include "vm/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/cpu.h"
@@ skipping 7910 matching lines @@
 
 RawLibrary* Library::MirrorsLibrary() {
   return Isolate::Current()->object_store()->mirrors_library();
 }
 
 
 RawLibrary* Library::NativeWrappersLibrary() {
   return Isolate::Current()->object_store()->native_wrappers_library();
 }
 
-RawLibrary* Library::PlatformLibrary() {
-  return Isolate::Current()->object_store()->platform_library();
-}
-
 
 RawLibrary* Library::TypedDataLibrary() {
   return Isolate::Current()->object_store()->typed_data_library();
 }
 
 
 RawLibrary* Library::UtfLibrary() {
   return Isolate::Current()->object_store()->utf_library();
 }
 
@@ skipping 7643 matching lines @@
   return "_MirrorReference";
 }
 
 
 void MirrorReference::PrintToJSONStream(JSONStream* stream, bool ref) const {
   JSONObject jsobj(stream);
 }
 
 
 }  // namespace dart