Created methods to surface zone memory information for each isolate and thread in JSON.

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 RUNTIME_VM_ISOLATE_H_
 #define RUNTIME_VM_ISOLATE_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/atomic.h"
@@ skipping 450 matching lines @@
     return defer_finalization_count_--;
   }
 
   bool AllowClassFinalization() {
     ASSERT(defer_finalization_count_ >= 0);
     return defer_finalization_count_ == 0;
   }
 
 #ifndef PRODUCT
   void PrintJSON(JSONStream* stream, bool ref = true);
+  void PrintThreadsInfoToJSONObject(JSONObject* obj);

[siva, 2016/12/07 22:12:52]

Can these two methods PrintJSON and PrintThreadsInf... be const methods?

[bkonyi, 2016/12/08 18:04:14]

ServiceEvent requires an Isolate* argument and has a method isolate() which
returns an Isolate* as well. I'm not sure we could easily make changes to pass
an argument of type 'const Isolate* const' instead.

+  static void PrintAllIsolatesMemoryInfoToJSONLocked(JSONStream* stream);
 #endif
 
   // Mutator thread is used to aggregate compiler stats.
   CompilerStats* aggregate_compiler_stats() {
     return mutator_thread()->compiler_stats();
   }
 
   VMTagCounters* vm_tag_counters() { return &vm_tag_counters_; }
 
   bool IsReloading() const { return reload_context_ != NULL; }
@@ skipping 507 matching lines @@
   intptr_t* spawn_count_;
 
   Dart_IsolateFlags isolate_flags_;
   bool paused_;
   bool errors_are_fatal_;
 };
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_ISOLATE_H_