Add separate feature flag for VR CCT browsing.

chrome/browser/flag_descriptions.h

Index: chrome/browser/flag_descriptions.h
diff --git a/chrome/browser/flag_descriptions.h b/chrome/browser/flag_descriptions.h
index 28aff3a4a88030789a01b3196a70ad135b556fd2..5a3133c73e40f5c37bcce4e4eb87a61a2166cf2b 100644
--- a/chrome/browser/flag_descriptions.h
+++ b/chrome/browser/flag_descriptions.h
@@ -8,6 +8,7 @@
 // Includes needed for macros allowing conditional compilation of some strings.
 #include "build/build_config.h"
 #include "build/buildflag.h"
+#include "device/vr/features/features.h"
 #include "media/media_features.h"
 
 // This file declares strings used in chrome://flags. These messages are not
@@ -782,8 +783,10 @@ extern const char kWebrtcSrtpAesGcmDescription[];
 extern const char kWebrtcStunOriginName[];
 extern const char kWebrtcStunOriginDescription[];
 
+#if BUILDFLAG(ENABLE_VR)
 extern const char kWebvrExperimentalRenderingName[];
 extern const char kWebvrExperimentalRenderingDescription[];
+#endif  // ENABLE_VR
 
 extern const char kWebvrName[];
 extern const char kWebvrDescription[];
@@ -933,9 +936,16 @@ extern const char kEnableOskOverscrollDescription[];
 extern const char kEnableSpecialLocaleName[];
 extern const char kEnableSpecialLocaleDescription[];
 
+#if BUILDFLAG(ENABLE_VR)
+
 extern const char kEnableVrShellName[];
 extern const char kEnableVrShellDescription[];
 
+extern const char kVrCustomTabBrowsingName[];
+extern const char kVrCustomTabBrowsingDescription[];
+
+#endif  // BUILDFLAG(ENABLE_VR)
+
 extern const char kEnableWebapk[];
 extern const char kEnableWebapkDescription[];