Make fewer assumptions about the layout of api handles.

runtime/vm/dart_api_impl.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 "include/dart_api.h"
 
 #include "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/compiler.h"
 #include "vm/dart.h"
@@ skipping 112 matching lines @@
   ApiState* state = isolate->api_state();
   ASSERT(state != NULL);
   ASSERT(state->IsValidLocalHandle(object) ||
          state->IsValidPersistentHandle(object) ||
          state->IsValidWeakPersistentHandle(object) ||
          state->IsValidPrologueWeakPersistentHandle(object));
   ASSERT(FinalizablePersistentHandle::raw_offset() == 0 &&
          PersistentHandle::raw_offset() == 0 &&
          LocalHandle::raw_offset() == 0);
 #endif
-  return *(reinterpret_cast<RawObject**>(object));
+  return (reinterpret_cast<LocalHandle*>(object))->raw();
 }
 
 #define DEFINE_UNWRAP(type)                                                    \
   const type& Api::Unwrap##type##Handle(Isolate* iso,                          \
                                         Dart_Handle dart_handle) {             \
     const Object& obj = Object::Handle(iso, Api::UnwrapHandle(dart_handle));   \
     if (obj.Is##type()) {                                                      \
       return type::Cast(obj);                                                  \
     }                                                                          \
     return type::Handle(iso);                                                  \
@@ skipping 4042 matching lines @@
 DART_EXPORT void Dart_InitPerfEventsSupport(Dart_FileWriterFunction function) {
   Dart::set_perf_events_writer(function);
 }
 
 
 DART_EXPORT void Dart_InitFlowGraphPrinting(Dart_FileWriterFunction function) {
   Dart::set_flow_graph_writer(function);
 }
 
 }  // namespace dart