customtabs: Extract a redirect endpoint, and maybe connect to it.

chrome/browser/android/chrome_feature_list.cc

Index: chrome/browser/android/chrome_feature_list.cc
diff --git a/chrome/browser/android/chrome_feature_list.cc b/chrome/browser/android/chrome_feature_list.cc
index 6f97fcb3f8c3fc877fa3ac13d9f3e1fa873bd07d..a47c5f5c75c279a12d49f46576c2d6e8cc112e8a 100644
--- a/chrome/browser/android/chrome_feature_list.cc
+++ b/chrome/browser/android/chrome_feature_list.cc
@@ -53,6 +53,7 @@ const base::Feature* kFeaturesExposedToJava[] = {
     &kCCTBackgroundTab,
     &kCCTExternalLinkHandling,
     &kCCTPostMessageAPI,
+    &kCCTRedirectPreconnect,
     &kChromeHomeFeature,
     &kChromeHomeExpandButton,
     &kChromeHomeSwipeLogic,
@@ -135,6 +136,9 @@ const base::Feature kCCTExternalLinkHandling{"CCTExternalLinkHandling",
 const base::Feature kCCTPostMessageAPI{"CCTPostMessageAPI",
                                        base::FEATURE_ENABLED_BY_DEFAULT};
 
+const base::Feature kCCTRedirectPreconnect{"CCTRedirectPreconnect",
+                                           base::FEATURE_DISABLED_BY_DEFAULT};
+
 const base::Feature kChromeHomeFeature{"ChromeHome",
                                        base::FEATURE_DISABLED_BY_DEFAULT};