- fix some cases where we are using uninitialized memory

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 "vm/atomic.h"
@@ skipping 803 matching lines @@
   // Protect access to boxed_field_list_.
   Mutex* field_list_mutex_;
   // List of fields that became boxed and that trigger deoptimization.
   RawGrowableObjectArray* boxed_field_list_;
 
   // This guards spawn_count_. An isolate cannot complete shutdown and be
   // destroyed while there are child isolates in the midst of a spawn.
   Monitor* spawn_count_monitor_;
   intptr_t spawn_count_;
 
+#define ISOLATE_METRIC_VARIABLE(type, variable, name, unit)                    \
+  type metric_##variable##_;
+  ISOLATE_METRIC_LIST(ISOLATE_METRIC_VARIABLE);
+#undef ISOLATE_METRIC_VARIABLE
+
   // Has a reload ever been attempted?
   bool has_attempted_reload_;
   intptr_t no_reload_scope_depth_;  // we can only reload when this is 0.
   // Per-isolate copy of FLAG_reload_every.
   intptr_t reload_every_n_stack_overflow_checks_;
   IsolateReloadContext* reload_context_;
   int64_t last_reload_timestamp_;
 
-#define ISOLATE_METRIC_VARIABLE(type, variable, name, unit)                    \
-  type metric_##variable##_;
-  ISOLATE_METRIC_LIST(ISOLATE_METRIC_VARIABLE);
-#undef ISOLATE_METRIC_VARIABLE
-
 
   static Dart_IsolateCreateCallback create_callback_;
   static Dart_IsolateShutdownCallback shutdown_callback_;
 
   static void WakePauseEventHandler(Dart_Isolate isolate);
 
   // Manage list of existing isolates.
   static bool AddIsolateToList(Isolate* isolate);
   static void RemoveIsolateFromList(Isolate* isolate);
 
@@ skipping 143 matching lines @@
   intptr_t* spawn_count_;
 
   Dart_IsolateFlags isolate_flags_;
   bool paused_;
   bool errors_are_fatal_;
 };
 
 }  // namespace dart
 
 #endif  // VM_ISOLATE_H_