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

runtime/vm/dart_api_impl.cc

Index: runtime/vm/dart_api_impl.cc
diff --git a/runtime/vm/dart_api_impl.cc b/runtime/vm/dart_api_impl.cc
index 8ff2deb5d67f79af18fbb3ae1cc7074d99718e6e..dca2d0111504c7c1d3629f78af8a7eb10f5450a8 100644
--- a/runtime/vm/dart_api_impl.cc
+++ b/runtime/vm/dart_api_impl.cc
@@ -26,6 +26,7 @@
 #include "vm/lockers.h"
 #include "vm/isolate_reload.h"
 #include "vm/kernel_isolate.h"
+#include "vm/malloc_hooks.h"
 #include "vm/message.h"
 #include "vm/message_handler.h"
 #include "vm/native_entry.h"
@@ -1172,6 +1173,8 @@ DART_EXPORT char* Dart_Initialize(Dart_InitializeParams* params) {
         "Invalid Dart_InitializeParams version.");
   }
 
+  MallocHooks::Init();
+
   return Dart::InitOnce(params->vm_isolate_snapshot,
                         params->instructions_snapshot, params->data_snapshot,
                         params->create, params->shutdown, params->thread_exit,
@@ -1184,6 +1187,7 @@ DART_EXPORT char* Dart_Initialize(Dart_InitializeParams* params) {
 DART_EXPORT char* Dart_Cleanup() {
   CHECK_NO_ISOLATE(Isolate::Current());
   const char* err_msg = Dart::Cleanup();
+  MallocHooks::TearDown();
   if (err_msg != NULL) {
     return strdup(err_msg);
   }