Remove the no longer used kPACE connection option. No functional change.

chrome/browser/io_thread.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 CHROME_BROWSER_IO_THREAD_H_
 #define CHROME_BROWSER_IO_THREAD_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 328 matching lines @@
   static bool ShouldDisableInsecureQuic(
       const VariationParameters& quic_trial_params);
 
   // Returns true if the selection of the ephemeral port in bind() should be
   // performed by Chromium, and false if the OS should select the port.  The OS
   // option is used to prevent Windows from posting a security security warning
   // dialog.
   static bool ShouldEnableQuicPortSelection(
       const base::CommandLine& command_line);
 
-  // Returns true if QUIC packet pacing should be negotiated during the
-  // QUIC handshake.
-  static bool ShouldEnableQuicPacing(
-      const base::CommandLine& command_line,
-      const VariationParameters& quic_trial_params);
-
   // Returns true if QUIC should always require handshake confirmation during
   // the QUIC handshake.
   static bool ShouldQuicAlwaysRequireHandshakeConfirmation(
       const VariationParameters& quic_trial_params);
 
   // Returns true if QUIC should disable connection pooling.
   static bool ShouldQuicDisableConnectionPooling(
       const VariationParameters& quic_trial_params);
 
   // Returns the ratio of time to load QUIC sever information from disk cache to
@@ skipping 119 matching lines @@
   bool is_quic_allowed_by_policy_;
 
   const base::TimeTicks creation_time_;
 
   base::WeakPtrFactory<IOThread> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(IOThread);
 };
 
 #endif  // CHROME_BROWSER_IO_THREAD_H_