Fix WebSocketServer extension parser.

net/websockets/websocket_extension.cc

 // Copyright 2013 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/websockets/websocket_extension.h"
 
 #include <map>
 #include <string>
 
 #include "base/logging.h"
@@ skipping 27 matching lines @@
   std::multimap<std::string, std::string> this_parameters, other_parameters;
   for (const auto& p : parameters_) {
     this_parameters.insert(std::make_pair(p.name(), p.value()));
   }
   for (const auto& p : other.parameters_) {
     other_parameters.insert(std::make_pair(p.name(), p.value()));
   }
   return this_parameters == other_parameters;
 }
 
+std::string WebSocketExtension::ToString() const {
+  if (name_.empty()) {
+    return std::string();
+  }
+
+  std::string result = name_;
+
+  for (const auto& param : parameters_) {
+    result += "; " + param.name();
+    if (!param.HasValue())
+      continue;
+
+    result += "=";
+    const auto& value = param.value();
+    if (value.find('"') == std::string::npos) {
+      result += value;
+    } else {
+      result += '"';
+      for (const auto& c : value) {
+        if (c == '"') {
+          result += "\\\"";
+        } else {
+          result += c;
+        }
+      }
+      result += '"';
+    }
+  }
+  return result;
+}
+
 }  // namespace net