arc: Prepare ArcAuthEndpoint flag for finch experiment.

components/arc/arc_features.cc

Index: components/arc/arc_features.cc
diff --git a/components/arc/arc_features.cc b/components/arc/arc_features.cc
index 5cf10d6beebbc6872403ed20fbc6e4093f21302e..7b656d44a6c381db6b8ab691c386bdb5643fc0a2 100644
--- a/components/arc/arc_features.cc
+++ b/components/arc/arc_features.cc
@@ -6,9 +6,15 @@
 
 namespace arc {
 
+// Controls if Arc should use silent auth code request API.
+const base::Feature kArcUseAuthEndpointFeature {
+    "ArcUseAuthEndpoint", base::FEATURE_DISABLED_BY_DEFAULT
+};
+
 // Controls ACTION_BOOT_COMPLETED broadcast for third party applications on ARC.
 // When disabled, third party apps will not receive this broadcast.
-const base::Feature kBootCompletedBroadcastFeature{
-    "ArcBootCompletedBroadcast", base::FEATURE_ENABLED_BY_DEFAULT};
+const base::Feature kBootCompletedBroadcastFeature {
+    "ArcBootCompletedBroadcast", base::FEATURE_ENABLED_BY_DEFAULT
+};
 
 }  // namespace arc