Add GC stats to GC timeline events

runtime/vm/heap.cc

Index: runtime/vm/heap.cc
diff --git a/runtime/vm/heap.cc b/runtime/vm/heap.cc
index ef4e14cbe5d21520d732074f25da7c7a9fa3b4de..bb8d4469144f63d1a952a38e2f59c1160a9bc09f 100644
--- a/runtime/vm/heap.cc
+++ b/runtime/vm/heap.cc
@@ -381,6 +381,7 @@ void Heap::CollectNewSpaceGarbage(Thread* thread,
     UpdatePretenurePolicy();
     RecordAfterGC(kNew);
     PrintStats();
+    NOT_IN_PRODUCT(PrintStatsToTimeline(&tds));
     EndNewSpaceGC();
     if ((reason == kNewSpace) && old_space_.NeedsGarbageCollection()) {
       // Old collections should call the API callbacks.
@@ -403,6 +404,7 @@ void Heap::CollectOldSpaceGarbage(Thread* thread,
     old_space_.MarkSweep(invoke_api_callbacks);
     RecordAfterGC(kOld);
     PrintStats();
+    NOT_IN_PRODUCT(PrintStatsToTimeline(&tds));
     EndOldSpaceGC();
   }
 }
@@ -834,6 +836,64 @@ void Heap::PrintStats() {
 }
 
 
+void Heap::PrintStatsToTimeline(TimelineEventScope* event) {
+  if ((event == NULL) || !event->enabled()) {
+    return;
+  }
+  event->SetNumArguments(12);
+  event->FormatArgument(0,
+                        "Before.New.Used (kB)",
+                        "%" Pd "",
+                        RoundWordsToKB(stats_.before_.new_.used_in_words));
+  event->FormatArgument(1,
+                        "After.New.Used (kB)",
+                        "%" Pd "",
+                        RoundWordsToKB(stats_.after_.new_.used_in_words));
+  event->FormatArgument(2,
+                        "Before.Old.Used (kB)",
+                        "%" Pd "",
+                        RoundWordsToKB(stats_.before_.old_.used_in_words));
+  event->FormatArgument(3,
+                        "After.Old.Used (kB)",
+                        "%" Pd "",
+                        RoundWordsToKB(stats_.after_.old_.used_in_words));
+
+  event->FormatArgument(4,
+                        "Before.New.Capacity (kB)",
+                        "%" Pd "",
+                        RoundWordsToKB(stats_.before_.new_.capacity_in_words));
+  event->FormatArgument(5,
+                        "After.New.Capacity (kB)",
+                        "%" Pd "",
+                        RoundWordsToKB(stats_.after_.new_.capacity_in_words));
+  event->FormatArgument(6,
+                        "Before.Old.Capacity (kB)",
+                        "%" Pd "",
+                        RoundWordsToKB(stats_.before_.old_.capacity_in_words));
+  event->FormatArgument(7,
+                        "After.Old.Capacity (kB)",
+                        "%" Pd "",
+                        RoundWordsToKB(stats_.after_.old_.capacity_in_words));
+
+  event->FormatArgument(8,
+                        "Before.New.External (kB)",
+                        "%" Pd "",
+                        RoundWordsToKB(stats_.before_.new_.external_in_words));
+  event->FormatArgument(9,
+                        "After.New.External (kB)",
+                        "%" Pd "",
+                        RoundWordsToKB(stats_.after_.new_.external_in_words));
+  event->FormatArgument(10,
+                        "Before.Old.External (kB)",
+                        "%" Pd "",
+                        RoundWordsToKB(stats_.before_.old_.external_in_words));
+  event->FormatArgument(11,
+                        "After.Old.External (kB)",
+                        "%" Pd "",
+                        RoundWordsToKB(stats_.after_.old_.external_in_words));
+}
+
+
 NoHeapGrowthControlScope::NoHeapGrowthControlScope()
     : StackResource(Thread::Current()) {
     Heap* heap = reinterpret_cast<Isolate*>(isolate())->heap();