- Add different types for persistent and weak persistent handles

runtime/vm/dart_api_impl.h

Index: runtime/vm/dart_api_impl.h
===================================================================
--- runtime/vm/dart_api_impl.h	(revision 22905)
+++ runtime/vm/dart_api_impl.h	(working copy)
@@ -80,18 +80,18 @@
 
   // Validates and converts the passed in handle as a persistent handle.
   static PersistentHandle* UnwrapAsPersistentHandle(const ApiState& state,
-                                                    Dart_Handle object);
+                                                    Dart_PersistentHandle object);
 
   // Validates and converts the passed in handle as a weak persistent handle.
   static FinalizablePersistentHandle* UnwrapAsWeakPersistentHandle(
       const ApiState& state,
-      Dart_Handle object);
+      Dart_WeakPersistentHandle object);
 
   // Validates and converts the passed in handle as a prologue weak
   // persistent handle.
   static FinalizablePersistentHandle* UnwrapAsPrologueWeakPersistentHandle(
       const ApiState& state,
-      Dart_Handle object);
+      Dart_WeakPersistentHandle object);
 
   // Returns an Error handle if isolate is in an inconsistent state.
   // Returns a Success handle when no error condition exists.
@@ -154,6 +154,9 @@
   // Performs one-time initialization needed by the API.
   static void InitOnce();
 
+  // Allocates handles for objects in the VM isolate.
+  static void InitHandles();
+
   // Helper function to get the peer value of an external string object.
   static bool ExternalStringGetPeerHelper(Dart_Handle object, void** peer);
 
@@ -161,6 +164,9 @@
   // Thread local key used by the API. Currently holds the current
   // ApiNativeScope if any.
   static ThreadLocalKey api_native_key_;
+  static Dart_Handle true_handle_;
+  static Dart_Handle false_handle_;
+  static Dart_Handle null_handle_;
 
   friend class ApiNativeScope;
 };