Add separate feature flag for VR CCT browsing.

chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellDelegate.java

Index: chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellDelegate.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellDelegate.java b/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellDelegate.java
index 3620c6d304a6116cccf9d4c1e432516314b314f4..b554bea61c862e95304a1ef03bba297d0db9cab0 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellDelegate.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellDelegate.java
@@ -318,7 +318,11 @@ public class VrShellDelegate implements ApplicationStatus.ActivityStateListener,
     }
 
     private static boolean activitySupportsVrBrowsing(Activity activity) {
-        return activity instanceof ChromeTabbedActivity || activity instanceof CustomTabActivity;
+        if (activity instanceof ChromeTabbedActivity) return true;
+        if (activity instanceof CustomTabActivity) {
+            return ChromeFeatureList.isEnabled(ChromeFeatureList.VR_CUSTOM_TAB_BROWSING);
+        }
+        return false;
     }
 
     /**