Assume all providers may give zero suggest responses.

chrome/browser/autocomplete/history_quick_provider.cc

 // 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.
 
 #include "chrome/browser/autocomplete/history_quick_provider.h"
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/command_line.h"
@@ skipping 38 matching lines @@
 using history::ScoredHistoryMatches;
 
 bool HistoryQuickProvider::disabled_ = false;
 
 HistoryQuickProvider::HistoryQuickProvider(Profile* profile)
     : HistoryProvider(profile, AutocompleteProvider::TYPE_HISTORY_QUICK),
       languages_(profile_->GetPrefs()->GetString(prefs::kAcceptLanguages)) {
 }
 
 void HistoryQuickProvider::Start(const AutocompleteInput& input,
-                                 bool minimal_changes) {
+                                 bool minimal_changes,
+                                 bool called_due_to_focus) {
   matches_.clear();
-  if (disabled_)
+  if (disabled_ || called_due_to_focus)
     return;
 
   // Don't bother with INVALID and FORCED_QUERY.
   if ((input.type() == metrics::OmniboxInputType::INVALID) ||
       (input.type() == metrics::OmniboxInputType::FORCED_QUERY))
     return;
 
   autocomplete_input_ = input;
 
   // TODO(pkasting): We should just block here until this loads.  Any time
@@ skipping 219 matching lines @@
   if (index_for_testing_.get())
     return index_for_testing_.get();
 
   HistoryService* const history_service =
       HistoryServiceFactory::GetForProfile(profile_, Profile::EXPLICIT_ACCESS);
   if (!history_service)
     return NULL;
 
   return history_service->InMemoryIndex();
 }