Enable WebMIDI for Windows behind the flag

chrome/browser/about_flags.cc

 // 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.
 
 #include "chrome/browser/about_flags.h"
 
 #include <algorithm>
 #include <iterator>
 #include <map>
 #include <set>
@@ skipping 1635 matching lines @@
     IDS_FLAGS_ENABLE_STICKY_KEYS_DESCRIPTION,
     kOsCrOS,
     ENABLE_DISABLE_VALUE_TYPE(switches::kEnableStickyKeys,
                               switches::kDisableStickyKeys)
   },
 #endif
   {
     "enable-web-midi",
     IDS_FLAGS_ENABLE_WEB_MIDI_NAME,
     IDS_FLAGS_ENABLE_WEB_MIDI_DESCRIPTION,
-    kOsMac,
+    kOsMac | kOsWin,
     SINGLE_VALUE_TYPE(switches::kEnableWebMIDI)
   },
   {
     "enable-new-profile-management",
     IDS_FLAGS_ENABLE_NEW_PROFILE_MANAGEMENT_NAME,
     IDS_FLAGS_ENABLE_NEW_PROFILE_MANAGEMENT_DESCRIPTION,
     kOsMac | kOsWin | kOsLinux,
     SINGLE_VALUE_TYPE(switches::kNewProfileManagement)
   },
   {
@@ skipping 685 matching lines @@
 }
 
 const Experiment* GetExperiments(size_t* count) {
   *count = num_experiments;
   return experiments;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags