Do not send MAX_PUSH_ID frame if QuicSpdySession::SetMaxPushId() is called with same value as last sent MAX_PUSH_ID.

Client side behavior change.

PiperOrigin-RevId: 314509389
Change-Id: I85ab61dcc6bd19cd2ac0c27d019e346efcccc691

quic/core/http/quic_spdy_session.cc

diff --git a/quic/core/http/quic_spdy_session.cc b/quic/core/http/quic_spdy_session.cc
index 4e532de..751a4d7 100644
--- a/quic/core/http/quic_spdy_session.cc
+++ b/quic/core/http/quic_spdy_session.cc
@@ -1228,11 +1228,15 @@
   ietf_server_push_enabled_ = true;
 
   if (max_push_id_.has_value()) {
-    QUIC_DVLOG(1) << "Setting max_push_id to:  " << max_push_id
+    if (max_push_id == max_push_id_.value()) {
+      QUIC_DVLOG(1) << "Not changing max_push_id: " << max_push_id;
+      return;
+    }
+
+    QUIC_DVLOG(1) << "Setting max_push_id to: " << max_push_id
                   << " from: " << max_push_id_.value();
   } else {
-    QUIC_DVLOG(1) << "Setting max_push_id to:  " << max_push_id
-                  << " from unset";
+    QUIC_DVLOG(1) << "Setting max_push_id to: " << max_push_id << " from unset";
   }
   max_push_id_ = max_push_id;