Heapchecker: Add a new suppression for V8 AllocateBuffer leak.

tools/heapcheck/suppressions.txt

 # There are three kinds of suppressions in this file.
 # 1. third party stuff we have no control over
 #
 # 2. intentional unit test errors, or stuff that is somehow a false positive
 # in our own code, or stuff that is so trivial it's not worth fixing
 #
 # 3. Suppressions for real chromium bugs that are not yet fixed.
 # These should all be in chromium's bug tracking system (but a few aren't yet).
 # Periodically we should sweep this file and the bug tracker clean by
 # running overnight and removing outdated bugs/suppressions.
@@ skipping 1684 matching lines @@
    fun:v8::internal::StaticMarkingVisitor::VisitEmbeddedPointer
    fun:v8::internal::RelocInfo::Visit
    fun:v8::internal::Code::CodeIterateBody
    fun:v8::internal::StaticMarkingVisitor::VisitCode
    fun:v8::internal::StaticMarkingVisitor::IterateBody
    fun:v8::internal::IncrementalMarking::VisitObject
    fun:v8::internal::IncrementalMarking::ProcessMarkingDeque
    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
    ...
    fun:FilterBuilder
    fun:::LoadWhitelistsOnBlockingPoolThread
 }
 {
    bug_171547_c
    Heapcheck:Leak
    ...
@@ skipping 153 matching lines @@
 {
    bug_227301b
    Heapcheck:Leak
    ...
    fun:disk_cache::EntryImpl::PrepareTarget
    fun:disk_cache::EntryImpl::InternalWriteData
    fun:disk_cache::EntryImpl::WriteDataImpl
    fun:disk_cache::BackendIO::ExecuteEntryOperation
    fun:disk_cache::BackendIO::ExecuteOperation
 }