[Feature Policy] Add command-line flag and about://flags interface for Feature Policy

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 2056 matching lines @@
 #endif  // defined(OS_CHROMEOS)
     {"browser-task-scheduler", IDS_FLAGS_BROWSER_TASK_SCHEDULER_NAME,
      IDS_FLAGS_BROWSER_TASK_SCHEDULER_DESCRIPTION, kOsAll,
      ENABLE_DISABLE_VALUE_TYPE(switches::kEnableBrowserTaskScheduler,
                                switches::kDisableBrowserTaskScheduler)},
 #if defined(OS_ANDROID)
     {"enable-webapk", IDS_FLAGS_ENABLE_WEBAPK,
      IDS_FLAGS_ENABLE_WEBAPK_DESCRIPTION, kOsAndroid,
      SINGLE_VALUE_TYPE(switches::kEnableWebApk)},
 #endif
+    {"enable-feature-policy", IDS_FLAGS_FEATURE_POLICY_NAME,
+     IDS_FLAGS_FEATURE_POLICY_DESCRIPTION, kOsAll,
+     FEATURE_VALUE_TYPE(features::kFeaturePolicy)},
     // 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)) {}
   ~FlagsStateSingleton() {}
@@ skipping 170 matching lines @@
 const base::HistogramBase::Sample kBadSwitchFormatHistogramId = 0;
 
 const FeatureEntry* GetFeatureEntries(size_t* count) {
   *count = arraysize(kFeatureEntries);
   return kFeatureEntries;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags