Rewrite std::string("") to std::string(), Linux edition.

chrome/browser/extensions/api/declarative_webrequest/webrequest_rules_registry.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/extensions/api/declarative_webrequest/webrequest_rules_registry.h"
 
 #include <algorithm>
 #include <limits>
 #include <utility>
 
@@ skipping 166 matching lines @@
   for (RulesMap::iterator i = new_webrequest_rules.begin();
        i != new_webrequest_rules.end(); ++i) {
     i->second->conditions().GetURLMatcherConditionSets(&all_new_condition_sets);
     if (i->second->conditions().HasConditionsWithoutUrls())
       rules_with_untriggered_conditions_.insert(i->second.get());
   }
   url_matcher_.AddConditionSets(all_new_condition_sets);
 
   ClearCacheOnNavigation();
 
-  return "";
+  return std::string();
 }
 
 std::string WebRequestRulesRegistry::RemoveRulesImpl(
     const std::string& extension_id,
     const std::vector<std::string>& rule_identifiers) {
   // URLMatcherConditionSet IDs that can be removed from URLMatcher.
   std::vector<URLMatcherConditionSet::ID> remove_from_url_matcher;
 
   for (std::vector<std::string>::const_iterator i = rule_identifiers.begin();
        i != rule_identifiers.end(); ++i) {
@@ skipping 18 matching lines @@
 
     // Removes the owning references to (and thus deletes) the rule.
     webrequest_rules_.erase(webrequest_rules_entry);
   }
 
   // Clear URLMatcher based on condition_set_ids that are not needed any more.
   url_matcher_.RemoveConditionSets(remove_from_url_matcher);
 
   ClearCacheOnNavigation();
 
-  return "";
+  return std::string();
 }
 
 std::string WebRequestRulesRegistry::RemoveAllRulesImpl(
     const std::string& extension_id) {
   // Search all identifiers of rules that belong to extension |extension_id|.
   std::vector<std::string> rule_identifiers;
   for (RulesMap::iterator i = webrequest_rules_.begin();
        i != webrequest_rules_.end(); ++i) {
     const WebRequestRule::GlobalRuleId& global_rule_id = i->first;
     if (global_rule_id.first == extension_id)
@@ skipping 67 matching lines @@
     RuleTriggers::const_iterator rule_trigger = rule_triggers_.find(*url_match);
     CHECK(rule_trigger != rule_triggers_.end());
     if (!ContainsKey(*result, rule_trigger->second) &&
         rule_trigger->second->conditions().IsFulfilled(*url_match,
                                                        request_data))
       result->insert(rule_trigger->second);
   }
 }
 
 }  // namespace extensions