[VM/Runtime] Turn on isolate group metrics gathering in product mode

dart2js benchmarks use --print-metrics to track heap usage, with the
shift to running dart2js using aproduct mode AOT snapshot these
metrics are not printed resulting in errors from the benchmarks.
The size increase from turning on these isolate group metrics in product
mode is not very significant (about 2k).

TEST=ci

Change-Id: Ie9bbaecd57a2b45c27a158f6eb4988966a41ce67
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/405220
Reviewed-by: Ryan Macnak <[email protected]>
Commit-Queue: Siva Annamalai <[email protected]>

Author: a-siva

runtime/vm/isolate.cc

@@ -2504,20 +2504,22 @@ void Isolate::LowLevelShutdown() {
         "\tisolate:    %s\n",
         name());
   }
+#endif  // !defined(PRODUCT)
   if (FLAG_print_metrics) {
     LogBlock lb;
     OS::PrintErr("Printing metrics for %s\n", name());
 #define ISOLATE_GROUP_METRIC_PRINT(type, variable, name, unit)                 \
   OS::PrintErr("%s\n", isolate_group_->Get##variable##Metric()->ToString());
     ISOLATE_GROUP_METRIC_LIST(ISOLATE_GROUP_METRIC_PRINT)
 #undef ISOLATE_GROUP_METRIC_PRINT
+#if !defined(PRODUCT)
 #define ISOLATE_METRIC_PRINT(type, variable, name, unit)                       \
   OS::PrintErr("%s\n", metric_##variable##_.ToString());
     ISOLATE_METRIC_LIST(ISOLATE_METRIC_PRINT)
 #undef ISOLATE_METRIC_PRINT
+#endif  // !defined(PRODUCT)
     OS::PrintErr("\n");
   }
-#endif  // !defined(PRODUCT)
 }
 
 #if !defined(PRODUCT) && !defined(DART_PRECOMPILED_RUNTIME)

runtime/vm/metrics.cc

@@ -35,7 +35,6 @@ void Metric::InitInstance(IsolateGroup* isolate_group,
   unit_ = unit;
 }
 
-#if !defined(PRODUCT)
 void Metric::InitInstance(Isolate* isolate,
                           const char* name,
                           const char* description,
@@ -58,6 +57,7 @@ void Metric::InitInstance(const char* name,
   unit_ = unit;
 }
 
+#if !defined(PRODUCT)
 static const char* UnitString(intptr_t unit) {
   switch (unit) {
     case Metric::kCounter:
@@ -79,11 +79,13 @@ void Metric::PrintJSON(JSONStream* stream) {
   obj.AddProperty("name", name_);
   obj.AddProperty("description", description_);
   obj.AddProperty("unit", UnitString(unit()));
+
   if (isolate_ == nullptr && isolate_group_ == nullptr) {
     obj.AddFixedServiceId("vm/metrics/%s", name_);
   } else {
     obj.AddFixedServiceId("metrics/native/%s", name_);
   }
+
   // TODO(johnmccutchan): Overflow?
   double value_as_double = static_cast<double>(Value());
   obj.AddProperty("value", value_as_double);
@@ -180,11 +182,11 @@ int64_t MetricHeapUsed::Value() const {
          isolate_group()->heap()->UsedInWords(Heap::kOld) * kWordSize;
 }
 
-#if !defined(PRODUCT)
 int64_t MetricIsolateCount::Value() const {
   return Isolate::IsolateListLength();
 }
 
+#if !defined(PRODUCT)
 int64_t MetricCurrentRSS::Value() const {
   return Service::CurrentRSS();
 }

runtime/vm/metrics.h

@@ -60,10 +60,8 @@ class Metric {
 
   Metric();
 
-#if !defined(PRODUCT)
   static void Init();
   static void Cleanup();
-#endif  // !defined(PRODUCT)
 
   // Initialize a metric for an isolate.
   void InitInstance(Isolate* isolate,
@@ -82,9 +80,9 @@ class Metric {
 
   virtual ~Metric();
 
-#ifndef PRODUCT
+#if !defined(PRODUCT)
   void PrintJSON(JSONStream* stream);
-#endif  // !PRODUCT
+#endif  // !defined(PRODUCT)
 
   // Returns a zone allocated string.
   static char* ValueToString(int64_t value, Unit unit);
@@ -173,7 +171,6 @@ class MetricHeapNewExternal : public Metric {
   virtual int64_t Value() const;
 };
 
-#if !defined(PRODUCT)
 class MetricIsolateCount : public Metric {
  public:
   virtual int64_t Value() const;
@@ -188,7 +185,6 @@ class MetricPeakRSS : public Metric {
  public:
   virtual int64_t Value() const;
 };
-#endif  // !defined(PRODUCT)
 
 class MetricHeapUsed : public Metric {
  public: