diff --git a/quiche/http2/core/priority_write_scheduler.h b/quiche/http2/core/priority_write_scheduler.h
index 7335545..6f7b92f 100644
--- a/quiche/http2/core/priority_write_scheduler.h
+++ b/quiche/http2/core/priority_write_scheduler.h
@@ -45,28 +45,8 @@
  public:
   using typename WriteScheduler<StreamIdType>::StreamPrecedenceType;
 
-  // Creates scheduler with no streams.
-  PriorityWriteScheduler() : PriorityWriteScheduler(spdy::kHttp2RootStreamId) {}
-  explicit PriorityWriteScheduler(StreamIdType root_stream_id)
-      : root_stream_id_(root_stream_id) {}
-
   void RegisterStream(StreamIdType stream_id,
                       const StreamPrecedenceType& precedence) override {
-    // TODO(mpw): verify |precedence.is_spdy3_priority() == true| once
-    //   Http2PriorityWriteScheduler enabled for HTTP/2.
-
-    // parent_id not used here, but may as well validate it.  However,
-    // parent_id may legitimately not be registered yet--see b/15676312.
-    StreamIdType parent_id = precedence.parent_id();
-    QUICHE_DVLOG_IF(
-        1, parent_id != root_stream_id_ && !StreamRegistered(parent_id))
-        << "Parent stream " << parent_id << " not registered";
-
-    if (stream_id == root_stream_id_) {
-      QUICHE_BUG(spdy_bug_19_1)
-          << "Stream " << root_stream_id_ << " already registered";
-      return;
-    }
     auto stream_info = std::make_unique<StreamInfo>(
         StreamInfo{precedence.spdy3_priority(), stream_id, false});
     bool inserted =
@@ -107,16 +87,6 @@
 
   void UpdateStreamPrecedence(StreamIdType stream_id,
                               const StreamPrecedenceType& precedence) override {
-    // TODO(mpw): verify |precedence.is_spdy3_priority() == true| once
-    //   Http2PriorityWriteScheduler enabled for HTTP/2.
-
-    // parent_id not used here, but may as well validate it.  However,
-    // parent_id may legitimately not be registered yet--see b/15676312.
-    StreamIdType parent_id = precedence.parent_id();
-    QUICHE_DVLOG_IF(
-        1, parent_id != root_stream_id_ && !StreamRegistered(parent_id))
-        << "Parent stream " << parent_id << " not registered";
-
     auto it = stream_infos_.find(stream_id);
     if (it == stream_infos_.end()) {
       // TODO(mpw): add to stream_infos_ on demand--see b/15676312.
@@ -331,7 +301,6 @@
   PriorityInfo priority_infos_[spdy::kV3LowestPriority + 1];
   // StreamInfos for all registered streams.
   StreamInfoMap stream_infos_;
-  StreamIdType root_stream_id_;
 };
 
 }  // namespace http2
diff --git a/quiche/http2/core/priority_write_scheduler_test.cc b/quiche/http2/core/priority_write_scheduler_test.cc
index 9be325f..e94e522 100644
--- a/quiche/http2/core/priority_write_scheduler_test.cc
+++ b/quiche/http2/core/priority_write_scheduler_test.cc
@@ -51,16 +51,14 @@
   EXPECT_TRUE(scheduler_.StreamRegistered(1));
   EXPECT_EQ(1u, scheduler_.NumRegisteredStreams());
 
-  // Root stream counts as already registered.
-  EXPECT_QUICHE_BUG(
-      scheduler_.RegisterStream(kHttp2RootStreamId, SpdyStreamPrecedence(1)),
-      "Stream 0 already registered");
-
   // Try redundant registrations.
   EXPECT_QUICHE_BUG(scheduler_.RegisterStream(1, SpdyStreamPrecedence(1)),
                     "Stream 1 already registered");
+  EXPECT_EQ(1u, scheduler_.NumRegisteredStreams());
+
   EXPECT_QUICHE_BUG(scheduler_.RegisterStream(1, SpdyStreamPrecedence(2)),
                     "Stream 1 already registered");
+  EXPECT_EQ(1u, scheduler_.NumRegisteredStreams());
 
   scheduler_.RegisterStream(2, SpdyStreamPrecedence(3));
   EXPECT_EQ(2u, scheduler_.NumRegisteredStreams());
@@ -76,6 +74,7 @@
   // Try redundant unregistration.
   EXPECT_QUICHE_BUG(scheduler_.UnregisterStream(1), "Stream 1 not registered");
   EXPECT_QUICHE_BUG(scheduler_.UnregisterStream(2), "Stream 2 not registered");
+  EXPECT_EQ(0u, scheduler_.NumRegisteredStreams());
 }
 
 TEST_F(PriorityWriteSchedulerTest, RegisterStreamWithHttp2StreamDependency) {
diff --git a/quiche/quic/core/quic_session.cc b/quiche/quic/core/quic_session.cc
index 898a869..7f3312e 100644
--- a/quiche/quic/core/quic_session.cc
+++ b/quiche/quic/core/quic_session.cc
@@ -73,7 +73,6 @@
     : connection_(connection),
       perspective_(connection->perspective()),
       visitor_(owner),
-      write_blocked_streams_(connection->transport_version()),
       config_(config),
       stream_id_manager_(perspective(), connection->transport_version(),
                          kDefaultMaxStreamsPerConnection,
diff --git a/quiche/quic/core/quic_write_blocked_list.cc b/quiche/quic/core/quic_write_blocked_list.cc
index d54ccca..9e53c94 100644
--- a/quiche/quic/core/quic_write_blocked_list.cc
+++ b/quiche/quic/core/quic_write_blocked_list.cc
@@ -9,17 +9,11 @@
 
 namespace quic {
 
-QuicWriteBlockedList::QuicWriteBlockedList(QuicTransportVersion version)
-    : priority_write_scheduler_(QuicVersionUsesCryptoFrames(version)
-                                    ? std::numeric_limits<QuicStreamId>::max()
-                                    : 0),
-      last_priority_popped_(0) {
+QuicWriteBlockedList::QuicWriteBlockedList() : last_priority_popped_(0) {
   memset(batch_write_stream_id_, 0, sizeof(batch_write_stream_id_));
   memset(bytes_left_for_batch_write_, 0, sizeof(bytes_left_for_batch_write_));
 }
 
-QuicWriteBlockedList::~QuicWriteBlockedList() {}
-
 bool QuicWriteBlockedList::ShouldYield(QuicStreamId id) const {
   for (const auto& stream : static_stream_collection_) {
     if (stream.id == id) {
diff --git a/quiche/quic/core/quic_write_blocked_list.h b/quiche/quic/core/quic_write_blocked_list.h
index 30eb337..f0f86a8 100644
--- a/quiche/quic/core/quic_write_blocked_list.h
+++ b/quiche/quic/core/quic_write_blocked_list.h
@@ -25,10 +25,10 @@
 // Crypto stream > Headers stream > Data streams by requested priority.
 class QUIC_EXPORT_PRIVATE QuicWriteBlockedList {
  public:
-  explicit QuicWriteBlockedList(QuicTransportVersion version);
+  explicit QuicWriteBlockedList();
   QuicWriteBlockedList(const QuicWriteBlockedList&) = delete;
   QuicWriteBlockedList& operator=(const QuicWriteBlockedList&) = delete;
-  ~QuicWriteBlockedList();
+  ~QuicWriteBlockedList() = default;
 
   bool HasWriteBlockedDataStreams() const {
     return priority_write_scheduler_.HasReadyStreams();
diff --git a/quiche/quic/core/quic_write_blocked_list_test.cc b/quiche/quic/core/quic_write_blocked_list_test.cc
index ba02a08..c04b891 100644
--- a/quiche/quic/core/quic_write_blocked_list_test.cc
+++ b/quiche/quic/core/quic_write_blocked_list_test.cc
@@ -20,10 +20,6 @@
 constexpr bool kNotIncremental = false;
 
 class QuicWriteBlockedListTest : public QuicTestWithParam<bool> {
- public:
-  QuicWriteBlockedListTest()
-      : write_blocked_list_(AllSupportedVersions()[0].transport_version) {}
-
  protected:
   QuicWriteBlockedList write_blocked_list_;
 };