Add disabled origin trial feature list

chrome/browser/origin_trials/origin_trial_controller.h

 // Copyright (c) 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.
 
 #ifndef CHROME_BROWSER_ORIGIN_TRIALS_ORIGIN_TRIAL_CONTROLLER_H_
 #define CHROME_BROWSER_ORIGIN_TRIALS_ORIGIN_TRIAL_CONTROLLER_H_
 
 namespace base {
 class CommandLine;
 }
 
 class OriginTrialController {
  public:
   static const char kFieldTrialName[];
   static const char kPublicKeyFieldName[];
+  static const char kDisabledFeaturesFieldName[];
 
   // Updates the renderer command line to pass any relevant origin trial
   // configuration to the renderer at startup. Currently this can include an
-  // updated public key to use for validating tokens. This method is
-  // thread-safe.
+  // updated public key to use for validating tokens, and a list of experimental
+  // features to exclude from origin trials. This method is thread-safe.
   static void UpdateCommandLineFromFieldTrials(base::CommandLine* command_line);
 };
 
 #endif  // CHROME_BROWSER_ORIGIN_TRIALS_ORIGIN_TRIAL_CONTROLLER_H_