Implemented basic heap memory allocation tracking in MallocHooks using hooks registered with tcmall…

runtime/vm/dart.cc

Index: runtime/vm/dart.cc
diff --git a/runtime/vm/dart.cc b/runtime/vm/dart.cc
index 57f5cbe759f160cb13e4894006d30ffca83a1c70..d50189f68dd5f3a9e3bd71f77409373facca1201 100644
--- a/runtime/vm/dart.cc
+++ b/runtime/vm/dart.cc
@@ -17,6 +17,7 @@
 #include "vm/heap.h"
 #include "vm/isolate.h"
 #include "vm/kernel_isolate.h"
+#include "vm/malloc_hooks.h"
 #include "vm/message_handler.h"
 #include "vm/metrics.h"
 #include "vm/object.h"
@@ -154,6 +155,7 @@ char* Dart::InitOnce(const uint8_t* vm_isolate_snapshot,
   start_time_micros_ = OS::GetCurrentMonotonicMicros();
   VirtualMemory::InitOnce();
   OSThread::InitOnce();
+  MallocHooks::InitOnce();
   if (FLAG_support_timeline) {
     Timeline::InitOnce();
   }
@@ -491,7 +493,7 @@ const char* Dart::Cleanup() {
   if (FLAG_trace_shutdown) {
     OS::PrintErr("[+%" Pd64 "ms] SHUTDOWN: Done\n", UptimeMillis());
   }
-
+  MallocHooks::TearDown();
   return NULL;
 }