Web MIDI: add dynamic MidiManager instantiation support for Linux

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 <iterator>
 #include <map>
 #include <set>
 #include <utility>
@@ skipping 2181 matching lines @@
     {"show-arc-files-app", IDS_FLAGS_SHOW_ARC_FILES_APP_NAME,
      IDS_FLAGS_SHOW_ARC_FILES_APP_DESCRIPTION, kOsCrOS,
      FEATURE_VALUE_TYPE(arc::kShowArcFilesAppFeature)},
 #endif // defined(OS_CHROMEOS)
 
 #if defined(OS_ANDROID)
     {"aia-fetching", IDS_FLAGS_AIA_FETCHING_NAME,
      IDS_FLAGS_AIA_FETCHING_DESCRIPTION, kOsAndroid,
      FEATURE_VALUE_TYPE(net::CertVerifyProcAndroid::kAIAFetchingFeature)},
 #endif
+    {"enable-midi-manager-dynamic-instantiation",
+     IDS_FLAGS_ENABLE_MIDI_MANAGER_DYNAMIC_INSTANTIATION_NAME,
+     IDS_FLAGS_ENABLE_MIDI_MANAGER_DYNAMIC_INSTANTIATION_DESCRIPTION, kOsAll,
+     FEATURE_VALUE_TYPE(midi::features::kMidiManagerDynamicInstantiation)}
 
     // NOTE: Adding new command-line switches requires adding corresponding
     // entries to enum "LoginCustomFlags" in histograms.xml. See note in
     // histograms.xml and don't forget to run AboutFlagsHistogramTest unit test.
 };
 
 class FlagsStateSingleton {
  public:
   FlagsStateSingleton()
       : flags_state_(kFeatureEntries, arraysize(kFeatureEntries)) {}
@@ skipping 189 matching lines @@
 const base::HistogramBase::Sample kBadSwitchFormatHistogramId = 0;
 
 const FeatureEntry* GetFeatureEntries(size_t* count) {
   *count = arraysize(kFeatureEntries);
   return kFeatureEntries;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags