Updated native memory allocation profiling to use its own sample buffer instead of sharing a sample…

runtime/vm/malloc_hooks_tcmalloc.cc

Index: runtime/vm/malloc_hooks_tcmalloc.cc
diff --git a/runtime/vm/malloc_hooks_tcmalloc.cc b/runtime/vm/malloc_hooks_tcmalloc.cc
index e4a5b86044bd4a18984611e1b095cebef2feae48..e5a1a23e02c73a97c10694afe93ffeab55bc6f75 100644
--- a/runtime/vm/malloc_hooks_tcmalloc.cc
+++ b/runtime/vm/malloc_hooks_tcmalloc.cc
@@ -143,6 +143,12 @@ class AllocationInfo {
     }
   }
 
+  ~AllocationInfo() {
+    if (sample_ != NULL) {
+      Profiler::allocation_sample_buffer()->FreeAllocationSample(sample_);
+    }
+  }
+
   Sample* sample() const { return sample_; }
   intptr_t allocation_size() const { return allocation_size_; }