Return error object from Dart_Allocate when an error occurs.

runtime/vm/isolate.h

 // Copyright (c) 2013, 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_ISOLATE_H_
 #define VM_ISOLATE_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/thread.h"
 #include "vm/base_isolate.h"
 #include "vm/class_table.h"
 #include "vm/gc_callbacks.h"
 #include "vm/handles.h"
 #include "vm/megamorphic_cache_table.h"
 #include "vm/random.h"
 #include "vm/store_buffer.h"
 #include "vm/timer.h"
 
 namespace dart {
 
 // Forward declarations.
 class AbstractType;
 class ApiState;
 class Array;
 class Class;
 class CodeIndexTable;
 class Debugger;
 class DeoptContext;
+class Error;
 class Field;
 class Function;
 class HandleScope;
 class HandleVisitor;
 class Heap;
 class ICData;
 class Instance;
 class IsolateProfilerData;
 class IsolateSpawnState;
 class InterruptableThreadState;
@@ skipping 28 matching lines @@
   IsolateVisitor() {}
   virtual ~IsolateVisitor() {}
 
   virtual void VisitIsolate(Isolate* isolate) = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(IsolateVisitor);
 };
 
 #define REUSABLE_HANDLE_LIST(V)                                                \
+  V(Array)                                                                     \
+  V(Class)                                                                     \
+  V(Error)                                                                     \
+  V(Field)                                                                     \
+  V(Function)                                                                  \
+  V(Instance)                                                                  \
   V(Object)                                                                    \
-  V(Array)                                                                     \
   V(String)                                                                    \
-  V(Instance)                                                                  \
-  V(Function)                                                                  \
-  V(Field)                                                                     \
-  V(Class)                                                                     \
+  V(TypeArguments)                                                             \
   V(TypeParameter)                                                             \
-  V(TypeArguments)                                                             \
 
 class Isolate : public BaseIsolate {
  public:
   ~Isolate();
 
   static inline Isolate* Current() {
     return reinterpret_cast<Isolate*>(Thread::GetThreadLocal(isolate_key));
   }
 
   static void SetCurrent(Isolate* isolate);
@@ skipping 552 matching lines @@
   char* script_url_;
   char* library_url_;
   char* class_name_;
   char* function_name_;
   char* exception_callback_name_;
 };
 
 }  // namespace dart
 
 #endif  // VM_ISOLATE_H_