Do not delay most visited results.

chrome/browser/autocomplete/zero_suggest_provider.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // This file contains the zero-suggest autocomplete provider. This experimental
 // provider is invoked when the user focuses in the omnibox prior to editing,
 // and generates search query suggestions based on the current URL.
 
 #ifndef CHROME_BROWSER_AUTOCOMPLETE_ZERO_SUGGEST_PROVIDER_H_
 #define CHROME_BROWSER_AUTOCOMPLETE_ZERO_SUGGEST_PROVIDER_H_
@@ skipping 101 matching lines @@
   AutocompleteMatch MatchForCurrentURL();
 
   // When the user is in the Most Visited field trial, we ask the TopSites
   // service for the most visited URLs during Run().  It calls back to this
   // function to return those |urls|.
   void OnMostVisitedUrlsAvailable(const history::MostVisitedURLList& urls);
 
   // Returns the relevance score for the verbatim result.
   int GetVerbatimRelevance() const;
 
-  // Whether we can show zero suggest on |current_page_url| without
-  // sending |current_page_url| as a parameter to the server at |suggest_url|.
-  bool CanShowZeroSuggestWithoutSendingURL(const GURL& suggest_url,
-                                           const GURL& current_page_url) const;
+  // Whether we can show zero suggest without sending |current_page_url| to
+  // |suggest_url| search provider. Also checks that other conditions for
+  // non-contextual zero suggest are satisfied.
+  bool ShouldShowNonContextualZeroSuggest(const GURL& suggest_url,
+                                          const GURL& current_page_url) const;
 
   // Checks whether we have a set of zero suggest results cached, and if so
   // populates |matches_| with cached results.
   void MaybeUseCachedSuggestions();
 
   AutocompleteProviderListener* listener_;
   Profile* profile_;
 
   // The URL for which a suggestion fetch is pending.
   std::string current_query_;
@@ skipping 13 matching lines @@
 
   // Contains suggest and navigation results as well as relevance parsed from
   // the response for the most recent zero suggest input URL.
   SearchSuggestionParser::Results results_;
 
   // Whether we are currently showing cached zero suggest results.
   bool results_from_cache_;
 
   history::MostVisitedURLList most_visited_urls_;
 
+  // Whether we are waiting for a most visited visited urls callback to run.
+  bool most_visited_urls_requested_;

[Mark P, 2014/10/22 19:11:23]

optional nit: consider calling this something like
most_visited_urls_request_pending_ or waiting_for_most_visited_urls_request_.
With the current name, I found it surprising when you set it to false
immediately after you received results.

[Maria, 2014/10/23 20:34:26]

Done.

+
   // For callbacks that may be run after destruction.
   base::WeakPtrFactory<ZeroSuggestProvider> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ZeroSuggestProvider);
 };
 
 #endif  // CHROME_BROWSER_AUTOCOMPLETE_ZERO_SUGGEST_PROVIDER_H_