Fix for issue 28638 - flakiness on dartkp-dart-precompiled caused by MallocHooks

runtime/vm/malloc_hooks_unsupported.cc

Index: runtime/vm/malloc_hooks_unsupported.cc
diff --git a/runtime/vm/malloc_hooks_unsupported.cc b/runtime/vm/malloc_hooks_unsupported.cc
index 47d0a0bbed5ac0647c1face21b9bf31aa57c611f..733e3ded74efdad658a44870dfedb9d540701805 100644
--- a/runtime/vm/malloc_hooks_unsupported.cc
+++ b/runtime/vm/malloc_hooks_unsupported.cc
@@ -25,11 +25,16 @@ void MallocHooks::ResetStats() {
 }
 
 
-bool MallocHooks::Initialized() {
+bool MallocHooks::Active() {
   return false;
 }
 
 
+void MallocHooks::PrintToJSONObject(JSONObject* jsobj) {
+  // Do nothing.
+}
+
+
 intptr_t MallocHooks::allocation_count() {
   return 0;
 }