Don't set QUIC's write alarm if we are connection flow control blocked.

net/quic/quic_write_blocked_list.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 #ifndef NET_QUIC_QUIC_WRITE_BLOCKED_LIST_H_
 #define NET_QUIC_QUIC_WRITE_BLOCKED_LIST_H_
 
 #include <set>
 
 #include "net/base/net_export.h"
 #include "net/quic/quic_protocol.h"
 #include "net/spdy/write_blocked_list.h"
 
 namespace net {
 
 // Keeps tracks of the QUIC streams that have data to write, sorted by
 // priority.  QUIC stream priority order is:
 // Crypto stream > Headers stream > Data streams by requested priority.
 class NET_EXPORT_PRIVATE QuicWriteBlockedList {
  private:
   typedef WriteBlockedList<QuicStreamId> QuicWriteBlockedListBase;
 
  public:
   static const QuicPriority kHighestPriority;
   static const QuicPriority kLowestPriority;
 
   QuicWriteBlockedList();
   ~QuicWriteBlockedList();
 
-  bool HasWriteBlockedStreams() const {
-    return crypto_stream_blocked_ ||
-        headers_stream_blocked_ ||
-        base_write_blocked_list_.HasWriteBlockedStreams();
+  bool HasWriteBlockedDataStreams() const {
+    return base_write_blocked_list_.HasWriteBlockedStreams();
+  }
+
+  bool HasWriteBlockedCryptoOrHeadersStream() const {
+    return crypto_stream_blocked_ || headers_stream_blocked_;
   }
 
   size_t NumBlockedStreams() const {
     size_t num_blocked = base_write_blocked_list_.NumBlockedStreams();
     if (crypto_stream_blocked_) {
       ++num_blocked;
     }
     if (headers_stream_blocked_) {
       ++num_blocked;
     }
@@ skipping 38 matching lines @@
       DVLOG(1) << "Stream " << stream_id << " already in write blocked list.";
       return;
     }
 
     base_write_blocked_list_.PushBack(
         stream_id, static_cast<SpdyPriority>(priority));
     blocked_streams_.insert(stream_id);
     return;
   }
 
+  bool crypto_stream_blocked() const { return crypto_stream_blocked_; }
+  bool headers_stream_blocked() const { return headers_stream_blocked_; }
+
  private:
   QuicWriteBlockedListBase base_write_blocked_list_;
   bool crypto_stream_blocked_;
   bool headers_stream_blocked_;
 
   // Keep track of write blocked streams in a set for faster membership checking
   // than iterating over the base_write_blocked_list_. The contents of this set
   // should mirror the contents of base_write_blocked_list_.
   std::set<QuicStreamId> blocked_streams_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicWriteBlockedList);
 };
 
 }  // namespace net
 
 
 #endif  // NET_QUIC_QUIC_WRITE_BLOCKED_LIST_H_