Updated redirect chain related TODO.

ios/chrome/browser/tabs/tab.mm

Index: ios/chrome/browser/tabs/tab.mm
diff --git a/ios/chrome/browser/tabs/tab.mm b/ios/chrome/browser/tabs/tab.mm
index b5e12d3765c2add415dff86d912e2a3beaf136a6..776f2a7b2de88d81f4e727a3c50a6541eb764fc1 100644
--- a/ios/chrome/browser/tabs/tab.mm
+++ b/ios/chrome/browser/tabs/tab.mm
@@ -1018,7 +1018,7 @@ void TabInfoBarObserver::OnInfoBarReplaced(infobars::InfoBar* old_infobar,
          !urlSpec.compare(0, urlSpecLength - 1, originalURL.spec()))) {
       redirects.push_back(referrer.url);
     }
-    // TODO(crbug.com/661670): the redirect chain is not constructed the same
+    // TODO(crbug.com/703872): the redirect chain is not constructed the same
     // way as upstream so this part needs to be revised.
     redirects.push_back(originalURL);
     redirects.push_back(url);