Remove empty-string comparisons.

webrtc/modules/audio_processing/test/audio_processing_unittest.cc

 /*
  *  Copyright (c) 2012 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 251 matching lines @@
   if (num_output_channels == 1) {
     ss << "mono";
   } else if (num_output_channels == 2) {
     ss << "stereo";
   } else {
     assert(false);
   }
   ss << output_rate / 1000 << "_pcm";
 
   std::string filename = ss.str();
-  if (temp_filenames[filename] == "")
+  if (temp_filenames[filename].empty())
     temp_filenames[filename] = test::TempFilename(test::OutputPath(), filename);
   return temp_filenames[filename];
 }
 
 void ClearTempFiles() {
   for (auto& kv : temp_filenames)
     remove(kv.second.c_str());
 }
 
 void OpenFileAndReadMessage(const std::string filename,
@@ skipping 2337 matching lines @@
         std::tr1::make_tuple(16000, 16000, 32000, 40),
         std::tr1::make_tuple(16000, 16000, 16000, 0)));
 #endif
 
 // TODO(henrike): re-implement functionality lost when removing the old main
 //                function. See
 //                https://code.google.com/p/webrtc/issues/detail?id=1981
 
 }  // namespace
 }  // namespace webrtc