Add Socket::ReadIfReady()

net/socket/ssl_client_socket_impl.h

 // Copyright (c) 2012 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_SOCKET_SSL_CLIENT_SOCKET_IMPL_H_
 #define NET_SOCKET_SSL_CLIENT_SOCKET_IMPL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 109 matching lines @@
   void DumpMemoryStats(SocketMemoryStats* stats) const override;
 
   // Dumps memory allocation stats. |pmd| is the browser process memory dump.
   static void DumpSSLClientSessionMemoryStats(
       base::trace_event::ProcessMemoryDump* pmd);
 
   // Socket implementation.
   int Read(IOBuffer* buf,
            int buf_len,
            const CompletionCallback& callback) override;
+  int ReadIfReady(IOBuffer* buf,
+                  int buf_len,
+                  const CompletionCallback& callback) override;
   int Write(IOBuffer* buf,
             int buf_len,
             const CompletionCallback& callback) override;
   int SetReceiveBufferSize(int32_t size) override;
   int SetSendBufferSize(int32_t size) override;
 
   // SocketBIOAdapter implementation:
   void OnReadReady() override;
   void OnWriteReady() override;
 
@@ skipping 12 matching lines @@
   int DoChannelIDLookup();
   int DoChannelIDLookupComplete(int result);
   int DoVerifyCert(int result);
   int DoVerifyCertComplete(int result);
   void DoConnectCallback(int result);
   void UpdateServerCert();
 
   void OnHandshakeIOComplete(int result);
 
   int DoHandshakeLoop(int last_io_result);
-  int DoPayloadRead();
+  int DoPayloadRead(IOBuffer* buf, int buf_len);

[Bence, 2017/03/03 16:33:41]

Optional: add a comment about whether this method saves a reference to |buf|. 
(Optional because my understanding is that private methods are not part of the
public API therefore it is not required to document them as rigorously.)

[xunjieli, 2017/03/03 19:41:06]

Acknowledged.

   int DoPayloadWrite();
 
   // Called when an asynchronous event completes which may have blocked the
   // pending Connect, Read or Write calls, if any. Retries all state machines
   // and, if complete, runs the respective callbacks.
   void RetryAllOperations();
 
   int VerifyCT();
 
   // Callback from the SSL layer that indicates the remote server is requesting
@@ skipping 179 matching lines @@
   // True if PKP is bypassed due to a local trust anchor.
   bool pkp_bypassed_;
 
   NetLogWithSource net_log_;
   base::WeakPtrFactory<SSLClientSocketImpl> weak_factory_;
 };
 
 }  // namespace net
 
 #endif  // NET_SOCKET_SSL_CLIENT_SOCKET_IMPL_H_