Add chrome flags entry for ChromeVox ARC support

chrome/browser/about_flags.cc

Index: chrome/browser/about_flags.cc
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 100372a85018600422871d600dbf87631630ba45..1df0161301acd53f26251c8c205c57214f124033 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -2325,6 +2325,12 @@ const FeatureEntry kFeatureEntries[] = {
      FEATURE_VALUE_TYPE(chrome::android::kCustomFeedbackUi)},
 #endif  // OS_ANDROID
 
+#if defined(OS_CHROMEOS)
+    {"enable-chromevox-arc-support", IDS_FLAGS_SHOW_ARC_FILES_APP_NAME,
+     IDS_FLAGS_ENABLE_CHROMEVOX_ARC_SUPPORT_DESCRIPTION, kOsCrOS,
+     SINGLE_VALUE_TYPE(chromeos::switches::kEnableChromeVoxArcSupport)},
+#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.