Emit session-level WINDOW_UPDATEs less frequently.

net/spdy/spdy_session.cc

Index: net/spdy/spdy_session.cc
diff --git a/net/spdy/spdy_session.cc b/net/spdy/spdy_session.cc
index db791e466b125387d1b4eb028e13d0de20803628..a04ca7b36ecceb04ae7bfa170c9f8224a37ad6ae 100644
--- a/net/spdy/spdy_session.cc
+++ b/net/spdy/spdy_session.cc
@@ -608,6 +608,7 @@ SpdySession::SpdySession(
     bool enable_compression,
     bool enable_ping_based_connection_checking,
     NextProto default_protocol,
+    size_t session_max_recv_window_size,
     size_t stream_initial_recv_window_size,
     size_t initial_max_concurrent_streams,
     size_t max_concurrent_streams_limit,
@@ -654,13 +655,16 @@ SpdySession::SpdySession(
       check_ping_status_pending_(false),
       send_connection_header_prefix_(false),
       flow_control_state_(FLOW_CONTROL_NONE),
+      session_send_window_size_(0),
+      session_max_recv_window_size_(session_max_recv_window_size == 0
+                                        ? kDefaultInitialRecvWindowSize
+                                        : session_max_recv_window_size),
+      session_recv_window_size_(0),
+      session_unacked_recv_window_bytes_(0),
       stream_initial_send_window_size_(GetInitialWindowSize(default_protocol)),
       stream_initial_recv_window_size_(stream_initial_recv_window_size == 0
                                            ? kDefaultInitialRecvWindowSize
                                            : stream_initial_recv_window_size),
-      session_send_window_size_(0),
-      session_recv_window_size_(0),
-      session_unacked_recv_window_bytes_(0),
       net_log_(BoundNetLog::Make(net_log, NetLog::SOURCE_HTTP2_SESSION)),
       verify_domain_authentication_(verify_domain_authentication),
       enable_sending_initial_data_(enable_sending_initial_data),
@@ -2786,15 +2790,20 @@ void SpdySession::SendInitialData() {
 
   // Next, notify the server about our initial recv window size.
   if (flow_control_state_ == FLOW_CONTROL_STREAM_AND_SESSION) {
+    if (session_max_recv_window_size_ == 0) {
+      session_max_recv_window_size_ = kDefaultInitialRecvWindowSize;
+    }
     // Bump up the receive window size to the real initial value. This
     // has to go here since the WINDOW_UPDATE frame sent by
     // IncreaseRecvWindowSize() call uses |buffered_spdy_framer_|.
-    DCHECK_GT(kDefaultInitialRecvWindowSize, session_recv_window_size_);
     // This condition implies that |kDefaultInitialRecvWindowSize| -
     // |session_recv_window_size_| doesn't overflow.
-    DCHECK_GT(session_recv_window_size_, 0);
-    IncreaseRecvWindowSize(
-        kDefaultInitialRecvWindowSize - session_recv_window_size_);
+    DCHECK_GE(session_max_recv_window_size_, session_recv_window_size_);
+    DCHECK_GE(session_recv_window_size_, 0);
+    if (session_max_recv_window_size_ > session_recv_window_size_) {
+      IncreaseRecvWindowSize(session_max_recv_window_size_ -
+                             session_recv_window_size_);
+    }
   }
 
   if (protocol_ <= kProtoSPDY31) {
@@ -3190,8 +3199,7 @@ void SpdySession::IncreaseRecvWindowSize(int32 delta_window_size) {
                                delta_window_size, session_recv_window_size_));
 
   session_unacked_recv_window_bytes_ += delta_window_size;
-  if (session_unacked_recv_window_bytes_ >
-      GetInitialWindowSize(protocol_) / 2) {
+  if (session_unacked_recv_window_bytes_ > session_max_recv_window_size_ / 2) {
     SendWindowUpdateFrame(kSessionFlowControlStreamId,
                           session_unacked_recv_window_bytes_,
                           HIGHEST);