AllocationProfiler: introduce allocation_profiler flag in V8 api.

src/heap-snapshot-generator.cc

Index: src/heap-snapshot-generator.cc
diff --git a/src/heap-snapshot-generator.cc b/src/heap-snapshot-generator.cc
index 10d113c3d17495aaada76aebd1bab8085ba9e0eb..029f67b2c1762360410dea8ac1cf59e708b9fa47 100644
--- a/src/heap-snapshot-generator.cc
+++ b/src/heap-snapshot-generator.cc
@@ -484,7 +484,7 @@ SnapshotObjectId HeapObjectsMap::FindOrAddEntry(Address addr,
         static_cast<int>(reinterpret_cast<intptr_t>(entry->value));
     EntryInfo& entry_info = entries_.at(entry_index);
     entry_info.accessed = accessed;
-    if (FLAG_heap_profiler_trace_objects) {
+    if (FLAG_heap_profiler_trace_objects && entry_info.size != size) {
       PrintF("Update object size : %p with old size %d and new size %d\n",
              addr,
              entry_info.size,
@@ -618,7 +618,6 @@ int HeapObjectsMap::FindUntrackedObjects() {
     for (int i = 0; i < heap_objects.length(); ++i) {
       const HeapObjectInfo& object_info = heap_objects[i];
       if (!object_info.IsValid()) {
-        ++untracked;
         if (last_printed_object != i - 1) {
           if (i > 0) {
             PrintF("%d objects were skipped\n", i - 1 - last_printed_object);