Restrict transmission of external exp ids to signed in users.

chrome/browser/android/contextualsearch/contextual_search_delegate.cc

Index: chrome/browser/android/contextualsearch/contextual_search_delegate.cc
diff --git a/chrome/browser/android/contextualsearch/contextual_search_delegate.cc b/chrome/browser/android/contextualsearch/contextual_search_delegate.cc
index 30023957026f5d73b65416eb09eebb9bb3fa1cd8..1c00112ca7c6aaf63e1a3a139e41a1574dbc85dd 100644
--- a/chrome/browser/android/contextualsearch/contextual_search_delegate.cc
+++ b/chrome/browser/android/contextualsearch/contextual_search_delegate.cc
@@ -139,7 +139,7 @@ void ContextualSearchDelegate::ContinueSearchTermResolutionRequest() {
   variations::AppendVariationHeaders(
       search_term_fetcher_->GetOriginalURL(),
       false,  // Impossible to be incognito at this point.
-      false, &headers);
+      false, false, &headers);
   search_term_fetcher_->SetExtraRequestHeaders(headers.ToString());
 
   SetDiscourseContextAndAddToHeader(*context_);