Count m(un)map for each stacktrace in MemoryRegionMap instead of HeapProfileTable.

third_party/tcmalloc/chromium/src/heap-checker.cc

Index: third_party/tcmalloc/chromium/src/heap-checker.cc
diff --git a/third_party/tcmalloc/chromium/src/heap-checker.cc b/third_party/tcmalloc/chromium/src/heap-checker.cc
index c53646b43ccc31d6e8c5470cd83ff91ca5d95548..ae69c7b971d255c6e69cab9adefd407a0ddfaedd 100644
--- a/third_party/tcmalloc/chromium/src/heap-checker.cc
+++ b/third_party/tcmalloc/chromium/src/heap-checker.cc
@@ -2203,7 +2203,7 @@ void HeapLeakChecker::BeforeConstructorsLocked() {
   RAW_CHECK(MallocHook::AddNewHook(&NewHook), "");
   RAW_CHECK(MallocHook::AddDeleteHook(&DeleteHook), "");
   constructor_heap_profiling = true;
-  MemoryRegionMap::Init(1);
+  MemoryRegionMap::Init(1, /* use_buckets */ false);
     // Set up MemoryRegionMap with (at least) one caller stack frame to record
     // (important that it's done before HeapProfileTable creation below).
   Allocator::Init();