Convert all symbols accessor to return read only handles so that it is not necessary to create a ne…

vm/dart_api_message.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/dart_api_message.h"
 #include "vm/object.h"
 #include "vm/snapshot_ids.h"
 #include "vm/symbols.h"
 #include "vm/unicode.h"
 
@@ skipping 206 matching lines @@
 Dart_CObject* ApiMessageReader::ReadVMSymbol(intptr_t object_id) {
   if (Symbols::IsVMSymbolId(object_id)) {
     intptr_t symbol_id = object_id - kMaxPredefinedObjectIds;
     Dart_CObject* object;
     if (vm_symbol_references_ != NULL &&
         (object = vm_symbol_references_[symbol_id]) != NULL) {
       return object;
     }
 
     if (vm_symbol_references_ == NULL) {
-      intptr_t size = sizeof(*vm_symbol_references_) * Symbols::kMaxId;
+      intptr_t size =
+          (sizeof(*vm_symbol_references_) * Symbols::kMaxPredefinedId);
       vm_symbol_references_ =
           reinterpret_cast<Dart_CObject**>(alloc_(NULL, 0, size));
       memset(vm_symbol_references_, 0, size);
     }
 
     RawOneByteString* str =
         reinterpret_cast<RawOneByteString*>(Symbols::GetVMSymbol(object_id));
     intptr_t len = Smi::Value(str->ptr()->length_);
     object = AllocateDartCObjectString(len);
     char* p = object->value.as_string;
@@ skipping 659 matching lines @@
     if (!success) {
       UnmarkAllCObjects(object);
       return false;
     }
   }
   UnmarkAllCObjects(object);
   return true;
 }
 
 }  // namespace dart