1. Restructure reusable handles to make individual Scopes for each handle type

runtime/vm/isolate.cc

Index: runtime/vm/isolate.cc
===================================================================
--- runtime/vm/isolate.cc	(revision 33332)
+++ runtime/vm/isolate.cc	(working copy)
@@ -273,8 +273,14 @@
 void BaseIsolate::AssertCurrent(BaseIsolate* isolate) {
   ASSERT(isolate == Isolate::Current());
 }
-#endif
+#endif  // defined(DEBUG)
 
+#if defined(DEBUG)
+#define REUSABLE_HANDLE_SCOPE_INIT(object)                                     \
+  reusable_##object##_handle_scope_active_(false),
+#else
+#define REUSABLE_HANDLE_SCOPE_INIT(object)
+#endif  // defined(DEBUG)
 
 #define REUSABLE_HANDLE_INITIALIZERS(object)                                   \
   object##_handle_(NULL),
@@ -321,11 +327,13 @@
       thread_state_(NULL),
       next_(NULL),
       REUSABLE_HANDLE_LIST(REUSABLE_HANDLE_INITIALIZERS)
+      REUSABLE_HANDLE_LIST(REUSABLE_HANDLE_SCOPE_INIT)
       reusable_handles_() {
   if (FLAG_print_object_histogram && (Dart::vm_isolate() != NULL)) {
     object_histogram_ = new ObjectHistogram(this);
   }
 }
+#undef REUSABLE_HANDLE_SCOPE_INIT
 #undef REUSABLE_HANDLE_INITIALIZERS
 
 
@@ -402,8 +410,7 @@
 
   // Setup the isolate specific resuable handles.
 #define REUSABLE_HANDLE_ALLOCATION(object)                                     \
-  result->object##_handle_ = result->AllocateReusableHandle<object>();         \
-
+  result->object##_handle_ = result->AllocateReusableHandle<object>();
   REUSABLE_HANDLE_LIST(REUSABLE_HANDLE_ALLOCATION)
 #undef REUSABLE_HANDLE_ALLOCATION