Remove empty-string comparisons.

webrtc/test/field_trial.cc

 /*
  *  Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 31 matching lines @@
 namespace test {
 // Note: this code is copied from src/base/metrics/field_trial.cc since the aim
 // is to mimic chromium --force-fieldtrials.
 void InitFieldTrialsFromString(const std::string& trials_string) {
   static const char kPersistentStringSeparator = '/';
 
   // Catch an error if this is called more than once.
   assert(field_trials_initiated_ == false);
   field_trials_initiated_ = true;
 
-  if (trials_string == "")
+  if (trials_string.empty())
     return;
 
   size_t next_item = 0;
   while (next_item < trials_string.length()) {
     size_t name_end = trials_string.find(kPersistentStringSeparator, next_item);
     if (name_end == trials_string.npos || next_item == name_end)
       break;
     size_t group_name_end = trials_string.find(kPersistentStringSeparator,
                                                name_end + 1);
     if (group_name_end == trials_string.npos || name_end + 1 == group_name_end)
@@ skipping 28 matching lines @@
   field_trials_ = std::map<std::string, std::string>();
   InitFieldTrialsFromString(config);
 }
 
 ScopedFieldTrials::~ScopedFieldTrials() {
   field_trials_ = previous_field_trials_;
 }
 
 }  // namespace test
 }  // namespace webrtc