Fix WebSocketServer extension parser.

net/websockets/websocket_extension.cc

Index: net/websockets/websocket_extension.cc
diff --git a/net/websockets/websocket_extension.cc b/net/websockets/websocket_extension.cc
index bf7a54bdbf3e17b79f4da23476525ea19d11a39e..c5e8e1720bf237e695df3c79a7efd8252e8f5ffc 100644
--- a/net/websockets/websocket_extension.cc
+++ b/net/websockets/websocket_extension.cc
@@ -8,6 +8,7 @@
 #include <string>
 
 #include "base/logging.h"
+#include "net/http/http_util.h"
 
 namespace net {
 
@@ -18,6 +19,8 @@ WebSocketExtension::Parameter::Parameter(const std::string& name,
                                          const std::string& value)
     : name_(name), value_(value) {
   DCHECK(!value.empty());
+  // |extension-param| must be a token.
+  DCHECK(HttpUtil::IsToken(value));
 }
 
 bool WebSocketExtension::Parameter::Equals(const Parameter& other) const {
@@ -45,4 +48,22 @@ bool WebSocketExtension::Equals(const WebSocketExtension& other) const {
   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;
+
+    // |extension-param| must be a token and we don't need to quote it.
+    DCHECK(HttpUtil::IsToken(param.value()));
+    result += "=" + param.value();
+  }
+  return result;
+}
+
 }  // namespace net