Server push cancellation: add methods in session layer to cancel push given the pushed url. Not in …

net/quic/core/quic_client_session_base.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_CLIENT_SESSION_BASE_H_
 #define NET_QUIC_QUIC_CLIENT_SESSION_BASE_H_
 
 #include <string>
 
 #include "base/macros.h"
@@ skipping 93 matching lines @@
   virtual void DeletePromised(QuicClientPromisedInfo* promised);
 
   virtual void OnPushStreamTimedOut(QuicStreamId stream_id);
 
   // Sends Rst for the stream, and makes sure that future calls to
   // IsClosedStream(id) return true, which ensures that any subsequent
   // frames related to this stream will be ignored (modulo flow
   // control accounting).
   void ResetPromised(QuicStreamId id, QuicRstStreamErrorCode error_code);
 
+  // Cancels the push if the push stream is unclaimed and active.
+  virtual void CancelPush(const GURL& url);

[Ryan Hamilton, 2016/10/27 17:00:25]

I don't think I understand why we need this method here since the .cc file has a
no-op implementation. I'm guessing this is some sort of polymorphism mechanism?

[Zhongyi Shi, 2016/10/27 17:57:30]

You are right. I don't need this anymore. I was thinking to make this function
more general so that we could also call it when push times out (which then
requires QuicClientSessionBase to have the method). Then I gave up... So yeah,
removing it now. Thanks for catching it!

+
   // Release headers stream's sequencer buffer if it's empty.
   void CloseStreamInner(QuicStreamId stream_id, bool locally_reset) override;
 
   // Returns true if there are no active requests and no promised streams.
   bool ShouldReleaseHeadersStreamSequencerBuffer() override;
 
   size_t get_max_promises() const {
     return max_open_incoming_streams() * kMaxPromisedStreamsMultiplier;
   }
 
@@ skipping 15 matching lines @@
   QuicClientPushPromiseIndex* push_promise_index_;
   QuicPromisedByIdMap promised_by_id_;
   QuicStreamId largest_promised_stream_id_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicClientSessionBase);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_CLIENT_SESSION_BASE_H_