Deprecate FLAGS_use_stream_frame_freelist.

net/quic/quic_protocol.cc

Index: net/quic/quic_protocol.cc
diff --git a/net/quic/quic_protocol.cc b/net/quic/quic_protocol.cc
index 192008e1967867b1b73aaf30b2ce25918cf757e3..acdbe14616f5edf5df30d2d31e2dc17ed1ec8319 100644
--- a/net/quic/quic_protocol.cc
+++ b/net/quic/quic_protocol.cc
@@ -108,17 +108,13 @@ QuicBufferAllocator::~QuicBufferAllocator() = default;
 void StreamBufferDeleter::operator()(char* buffer) const {
   if (allocator_ != nullptr && buffer != nullptr) {
     allocator_->Delete(buffer);
-    if (!FLAGS_use_stream_frame_freelist) {
-      allocator_->MarkAllocatorIdle();
-    }
   }
 }
 
 UniqueStreamBuffer NewStreamBuffer(QuicBufferAllocator* allocator,
                                    size_t size) {
-  return UniqueStreamBuffer(
-      allocator->New(size, FLAGS_use_stream_frame_freelist),
-      StreamBufferDeleter(allocator));
+  return UniqueStreamBuffer(allocator->New(size),
+                            StreamBufferDeleter(allocator));
 }
 
 QuicStreamFrame::QuicStreamFrame()