Add a URLRequest FTP fuzzer.

net/socket/fuzzed_socket.cc

 // Copyright 2016 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.
 
 #include "net/socket/fuzzed_socket.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/location.h"
@@ skipping 40 matching lines @@
   bool sync;
   int result;
 
   if (net_error_ != OK) {
     // If an error has already been generated, use it to determine what to do.
     result = net_error_;
     sync = !error_pending_;
   } else {
     // Otherwise, use |data_provider_|.
     sync = data_provider_->ConsumeBool();
-    result = data_provider_->ConsumeUint8();
-    if (result > buf_len)
-      result = buf_len;
+    std::string data = data_provider_->ConsumeRandomLengthString(buf_len);
+    result = data.size();
 
     if (result > 0) {
-      std::string data = data_provider_->ConsumeBytes(result);
-      result = data.size();
       std::copy(data.data(), data.data() + result, buf->data());
-    }
-
-    if (result == 0) {
-      net_error_ = ConsumeReadWriteErrorFromData();
-      result = net_error_;
+    } else {
+      result = ConsumeReadWriteErrorFromData();
+      net_error_ = result;
       if (!sync)
         error_pending_ = true;
     }
   }
 
   // Graceful close of a socket returns OK, at least in theory. This doesn't
   // perfectly reflect real socket behavior, but close enough.
   if (result == ERR_CONNECTION_CLOSED)
     result = 0;
 
@@ skipping 188 matching lines @@
   }
   callback.Run(result);
 }
 
 void FuzzedSocket::OnConnectComplete(const CompletionCallback& callback,
                                      int result) {
   CHECK(connect_pending_);
   connect_pending_ = false;
   if (result < 0)
     error_pending_ = false;
+  net_error_ = result;

[mmenke, 2016/11/01 18:35:43]

This is a bug fix.  Basically, if connect succeeded asynchronously,
IsConnected[AndIdle] would always return false.  May be worth considering some
way to simulate the socket being disconnected / having data first during that
call, but beyond the scope of this CL.

   callback.Run(result);
 }
 
 }  // namespace net