DCHECK(result) keeps firing in AutocompleteHistoryManager::OnWebDataServiceRequestDone()

chrome/browser/autocomplete_history_manager.cc

 // Copyright (c) 2010 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_manager.h"
 
 #include <vector>
 
 #include "base/string16.h"
 #include "base/string_number_conversions.h"
@@ skipping 157 matching lines @@
     const WDTypedResult* result) {
   DCHECK(pending_query_handle_);
   pending_query_handle_ = 0;
 
   if (!*autofill_enabled_) {
     SendSuggestions(NULL);
     return;
   }
 
   DCHECK(result);
+  // Returning early here if |result| is NULL.  We've seen this happen on
+  // Linux due to NFS dismounting and causing sql failures.
+  // See http://crbug.com/68783.
+  if (!result) {
+    SendSuggestions(NULL);
+    return;
+  }
+
   DCHECK(result->GetType() == AUTOFILL_VALUE_RESULT);
   const WDResult<std::vector<string16> >* autofill_result =
       static_cast<const WDResult<std::vector<string16> >*>(result);
   std::vector<string16> suggestions = autofill_result->GetValue();
   SendSuggestions(&suggestions);
 }
 
 AutocompleteHistoryManager::AutocompleteHistoryManager(
     Profile* profile, WebDataService* wds) : tab_contents_(NULL),
                                              profile_(profile),
@@ skipping 45 matching lines @@
                                                        autofill_icons_,
                                                        autofill_unique_ids_));
   }
 
   query_id_ = 0;
   autofill_values_.clear();
   autofill_labels_.clear();
   autofill_icons_.clear();
   autofill_unique_ids_.clear();
 }