Credential Manager: Add the API to about:flags.

content/child/runtime_features.cc

 // Copyright 2013 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 "content/child/runtime_features.h"
 
 #include "base/command_line.h"
 #include "base/metrics/field_trial.h"
 #include "content/common/content_switches_internal.h"
 #include "content/public/common/content_switches.h"
@@ skipping 157 matching lines @@
     WebRuntimeFeatures::enablePreciseMemoryInfo(true);
 
   if (command_line.HasSwitch(switches::kEnableLayerSquashing))
     WebRuntimeFeatures::enableLayerSquashing(true);
 
   if (command_line.HasSwitch(switches::kEnableNetworkInformation) ||
       command_line.HasSwitch(
           switches::kEnableExperimentalWebPlatformFeatures)) {
     WebRuntimeFeatures::enableNetworkInformation(true);
   }
+
+  if (command_line.HasSwitch(switches::kEnableCredentialManagerAPI))
+    WebRuntimeFeatures::enableCredentialManagerAPI(true);
 }
 
 }  // namespace content