[DoNotSubmit] Added peak_memory_size to accounting-allocator.

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index 348724d9f04eaee3f27365a3e851ec42ef89a4b6..5a5254aaab0fe8ee576a0b7d945efe7fa3fbb15f 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -5498,6 +5498,7 @@ HeapStatistics::HeapStatistics()
       used_heap_size_(0),
       heap_size_limit_(0),
       malloced_memory_(0),
+      malloced_peak_memory_(0),
       does_zap_garbage_(0) {}
 
 HeapSpaceStatistics::HeapSpaceStatistics(): space_name_(0),
@@ -7391,6 +7392,8 @@ void Isolate::GetHeapStatistics(HeapStatistics* heap_statistics) {
   heap_statistics->heap_size_limit_ = heap->MaxReserved();
   heap_statistics->malloced_memory_ =
       isolate->allocator()->GetCurrentMemoryUsage();
+  heap_statistics->malloced_peak_memory_ =
+      isolate->allocator()->GetPeakMemoryUsage();
   heap_statistics->does_zap_garbage_ = heap->ShouldZapGarbage();
 }