Surfaced native heap memory allocation information to the Observatory

runtime/vm/service.cc

Index: runtime/vm/service.cc
diff --git a/runtime/vm/service.cc b/runtime/vm/service.cc
index 1a46007c99881f263a8b8f8f9104176ca8643c9a..20f1b34b60797eef9b2511dfdc80d961cd27f1ba 100644
--- a/runtime/vm/service.cc
+++ b/runtime/vm/service.cc
@@ -16,6 +16,7 @@
 #include "vm/debugger.h"
 #include "vm/isolate.h"
 #include "vm/lockers.h"
+#include "vm/malloc_hooks.h"
 #include "vm/message.h"
 #include "vm/message_handler.h"
 #include "vm/native_entry.h"
@@ -3801,6 +3802,9 @@ void Service::PrintJSONForVM(JSONStream* js, bool ref) {
   jsobj.AddProperty64("_maxRSS", OS::MaxRSS());
   jsobj.AddPropertyTimeMillis(
       "startTime", OS::GetCurrentTimeMillis() - Dart::UptimeMillis());
+  jsobj.AddProperty("_heapAllocatedMemoryUsage",

[Cutch, 2017/01/31 23:21:05]

if there is a way to detect if the malloc hooks are running, it is more standard
to do:

if (MallocHooks::Initialized()) {
  // add properties.
}

[bkonyi, 2017/01/31 23:37:05]

I've gone ahead and added MallocHooks::Initialized() since it was a rather quick
change.

+                    MallocHooks::heap_allocated_memory_in_bytes());
+  jsobj.AddProperty("_heapAllocationCount", MallocHooks::allocation_count());
   // Construct the isolate list.
   {
     JSONArray jsarr(&jsobj, "isolates");