gfe-relnote: Add NumRegisteredStreams interface to WriteScheduler and implements it in subclasses. No used in prod yet, not protected.

Also move WriteSchedulerType to third_party/spdy/spdy_protocol.h to allow it be used by QUIC.

PiperOrigin-RevId: 259786320
Change-Id: I71fd5b68be9c10bf47f576c3020af17f80212178

spdy/core/http2_priority_write_scheduler.h

diff --git a/spdy/core/http2_priority_write_scheduler.h b/spdy/core/http2_priority_write_scheduler.h
index 1f72fdb..d08d125 100644
--- a/spdy/core/http2_priority_write_scheduler.h
+++ b/spdy/core/http2_priority_write_scheduler.h
@@ -76,11 +76,9 @@
   PopNextReadyStreamAndPrecedence() override;
   size_t NumReadyStreams() const override;
   bool IsStreamReady(StreamIdType stream_id) const override;
+  size_t NumRegisteredStreams() const override;
   SpdyString DebugString() const override;
 
-  // Return the number of streams currently in the tree.
-  int num_streams() const;
-
  private:
   friend class test::Http2PriorityWriteSchedulerPeer<StreamIdType>;
 
@@ -201,11 +199,6 @@
 }
 
 template <typename StreamIdType>
-int Http2PriorityWriteScheduler<StreamIdType>::num_streams() const {
-  return all_stream_infos_.size();
-}
-
-template <typename StreamIdType>
 bool Http2PriorityWriteScheduler<StreamIdType>::StreamRegistered(
     StreamIdType stream_id) const {
   return SpdyContainsKey(all_stream_infos_, stream_id);
@@ -696,8 +689,14 @@
 }
 
 template <typename StreamIdType>
+size_t Http2PriorityWriteScheduler<StreamIdType>::NumRegisteredStreams() const {
+  return all_stream_infos_.size();
+}
+
+template <typename StreamIdType>
 SpdyString Http2PriorityWriteScheduler<StreamIdType>::DebugString() const {
-  return SpdyStrCat("Http2PriorityWriteScheduler {num_streams=", num_streams(),
+  return SpdyStrCat("Http2PriorityWriteScheduler {num_registered_streams=",
+                    NumRegisteredStreams(),
                     " num_ready_streams=", NumReadyStreams(), "}");
 }
 
@@ -757,15 +756,15 @@
     }
   }
 
-  // Make sure num_streams reflects the total number of streams the map
-  // contains.
-  if (total_streams != num_streams()) {
+  // Make sure NumRegisteredStreams() reflects the total number of streams the
+  // map contains.
+  if (total_streams != NumRegisteredStreams()) {
     SPDY_DLOG(INFO) << "Map contains incorrect number of streams.";
     return false;
   }
   // Validate the validation function; we should have visited each stream twice
   // (except for the root)
-  DCHECK(streams_visited == 2 * num_streams() - 1);
+  DCHECK(streams_visited == 2 * NumRegisteredStreams() - 1);
   return true;
 }