Fallback to MostVisited when pers 0-query is on but user not signed-in

This CL adds a fallback to display MostVisited URLs when personalized
zero-query is enabled with ChromeHomePersonalizedOmniboxSuggestions but
the user is not signed-in.

TBR=rohitrao
for mechanical changes to ios/c/b/a/*

Bug: 781994
Change-Id: Id4f46c74115d88003d34df9e6b93190cf4c97368
Reviewed-on: https://chromium-review.googlesource.com/796451
Commit-Queue: Gheorghe Comanici <[email protected]>
Reviewed-by: Rohit Rao <[email protected]>
Reviewed-by: Mark Pearson <[email protected]>
Cr-Commit-Position: refs/heads/master@{#520592}
diff --git a/chrome/browser/autocomplete/chrome_autocomplete_provider_client.h b/chrome/browser/autocomplete/chrome_autocomplete_provider_client.h
index 398da24d..0a357ff 100644
--- a/chrome/browser/autocomplete/chrome_autocomplete_provider_client.h
+++ b/chrome/browser/autocomplete/chrome_autocomplete_provider_client.h
@@ -48,6 +48,7 @@
   bool IsOffTheRecord() const override;
   bool SearchSuggestEnabled() const override;
   bool TabSyncEnabledAndUnencrypted() const override;
+  bool IsAuthenticated() const override;
   void Classify(
       const base::string16& text,
       bool prefer_keyword,