Fix WebSocketServer extension parser.

net/websockets/websocket_deflate_parameters.h

 // Copyright 2015 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_WEBSOCKETS_WEBSOCKET_DEFLATE_PARAMETERS_H_
 #define NET_WEBSOCKETS_WEBSOCKET_DEFLATE_PARAMETERS_H_
 
 #include <string>
 
 #include "base/logging.h"
@@ skipping 75 matching lines @@
   }
   void SetClientMaxWindowBits() {
     client_max_window_bits_ = WindowBits(0, true, false);
   }
   // |bits| must be valid as a max_window_bits value.
   void SetClientMaxWindowBits(int bits) {
     DCHECK(IsValidWindowBits(bits));
     client_max_window_bits_ = WindowBits(bits, true, true);
   }
 
+  int PermissiveServerMaxWindowBits() const {
+    return server_max_window_bits_.PermissiveBits();
+  }
+  int PermissiveClientMaxWindowBits() const {
+    return client_max_window_bits_.PermissiveBits();
+  }
+
   // Return true if |bits| is valid as a max_window_bits value.
   static bool IsValidWindowBits(int bits) { return 8 <= bits && bits <= 15; }
 
  private:
   struct WindowBits {
     WindowBits() : WindowBits(0, false, false) {}
     WindowBits(int16 bits, bool is_specified, bool has_value)
         : bits(bits), is_specified(is_specified), has_value(has_value) {}
 
+    int PermissiveBits() const { return is_specified && has_value ? bits : 15; }
+
     int16 bits;
     // True when "window bits" parameter appears in the parameters.
     bool is_specified;
     // True when "window bits" parameter has the value.
     bool has_value;
   };
 
   // |server_context_take_over_mode| is set to DO_NOT_TAKE_OVER_CONTEXT if and
   // only if |server_no_context_takeover| is set in the parameters.
   ContextTakeOverMode server_context_take_over_mode_ =
       WebSocketDeflater::TAKE_OVER_CONTEXT;
   // |client_context_take_over_mode| is set to DO_NOT_TAKE_OVER_CONTEXT if and
   // only if |client_no_context_takeover| is set in the parameters.
   ContextTakeOverMode client_context_take_over_mode_ =
       WebSocketDeflater::TAKE_OVER_CONTEXT;
   WindowBits server_max_window_bits_;
   WindowBits client_max_window_bits_;
 };
 
 }  // namespace net
 
 #endif  // NET_WEBSOCKETS_WEBSOCKET_DEFLATE_PARAMETERS_H_