Add flag for MTP write support.

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 2287 matching lines @@
 // disabled, flag guard enable-launcher-search-provider-api.
 #if defined(ENABLE_APP_LIST)
   {
     "enable-launcher-search-provider-api",
     IDS_FLAGS_ENABLE_LAUNCHER_SEARCH_PROVIDER_API,
     IDS_FLAGS_ENABLE_LAUNCHER_SEARCH_PROVIDER_API_DESCRIPTION,
     kOsCrOS,
     SINGLE_VALUE_TYPE(app_list::switches::kEnableLauncherSearchProviderApi)
   },
 #endif  // defined(ENABLE_APP_LIST)
+#if defined(OS_CHROMEOS)
+  {
+    "enable-mtp-write-support",
+    IDS_FLAG_ENABLE_MTP_WRITE_SUPPORT_NAME,
+    IDS_FLAG_ENABLE_MTP_WRITE_SUPPORT_DESCRIPTION,
+    kOsCrOS,
+    SINGLE_VALUE_TYPE(chromeos::switches::kEnableMtpWriteSupport)
+  },
+#endif  // defined(OS_CHROMEOS)
 
   // 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.
 };
 
 const Experiment* experiments = kExperiments;
 size_t num_experiments = arraysize(kExperiments);
 
 // Stores and encapsulates the little state that about:flags has.
@@ skipping 569 matching lines @@
 }
 
 const Experiment* GetExperiments(size_t* count) {
   *count = num_experiments;
   return experiments;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags