diff --git a/ipc/chromium/src/base/pickle.cc b/ipc/chromium/src/base/pickle.cc
--- a/ipc/chromium/src/base/pickle.cc
+++ b/ipc/chromium/src/base/pickle.cc
@@ -337,16 +337,17 @@ void Pickle::EndRead(PickleIterator& ite
   // DCHECK(iter.iter_.Done());
 }
 
 void Pickle::Truncate(PickleIterator* iter) {
   size_t dropped = buffers_.Truncate(iter->iter_);
   header_->payload_size -= dropped;
 }
 
+MOZ_TT_ALLOW_REORDER
 static const char kBytePaddingData[4] = {
     kBytePaddingMarker,
     kBytePaddingMarker,
     kBytePaddingMarker,
     kBytePaddingMarker,
 };
 
 static void WritePadding(Pickle::BufferList& buffers, uint32_t padding) {
