Heapchecker: Add a new suppression for V8 AllocateBuffer leak.

tools/heapcheck/suppressions.txt

Index: tools/heapcheck/suppressions.txt
diff --git a/tools/heapcheck/suppressions.txt b/tools/heapcheck/suppressions.txt
index 21bf2316db47d9142c892d472bbc614e16c281ce..39d13277b93117e24908e9eb52f07651a48aa867 100644
--- a/tools/heapcheck/suppressions.txt
+++ b/tools/heapcheck/suppressions.txt
@@ -1702,6 +1702,18 @@
    fun:v8::internal::IncrementalMarking::Step
 }
 {
+   bug_169678_a
+   Heapcheck:Leak
+   fun:v8::internal::SlotsBufferAllocator::AllocateBuffer
+   fun:v8::internal::SlotsBuffer::AddTo
+   fun:v8::internal::MarkCompactCollector::RecordSlot
+   fun:v8::internal::IncrementalMarkingMarkingVisitor::VisitPointers
+   ...
+   fun:v8::internal::Heap::CollectGarbage
+   ...
+   fun:v8::String::New
+}
+{
    bug_171547_b
    Heapcheck:Leak
    ...