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

media/filters/pipeline_integration_test_base.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 "media/filters/pipeline_integration_test_base.h"
 
 #include "base/bind.h"
 #include "base/memory/scoped_vector.h"
 #include "media/base/media_log.h"
 #include "media/filters/audio_renderer_impl.h"
@@ skipping 49 matching lines @@
                     expected_status);
 }
 
 void PipelineIntegrationTestBase::DemuxerNeedKeyCB(
     const std::string& type,
     scoped_ptr<uint8[]> init_data,
     int init_data_size) {
   DCHECK(init_data.get());
   DCHECK_GT(init_data_size, 0);
   CHECK(!need_key_cb_.is_null());
-  need_key_cb_.Run("", "", type, init_data.Pass(), init_data_size);
+  need_key_cb_.Run(
+      std::string(), std::string(), type, init_data.Pass(), init_data_size);
 }
 
 void PipelineIntegrationTestBase::OnEnded() {
   DCHECK(!ended_);
   ended_ = true;
   pipeline_status_ = PIPELINE_OK;
   message_loop_.PostTask(FROM_HERE, MessageLoop::QuitClosure());
 }
 
 bool PipelineIntegrationTestBase::WaitUntilOnEnded() {
@@ skipping 204 matching lines @@
   base::MD5Final(&digest, &md5_context_);
   return base::MD5DigestToBase16(digest);
 }
 
 std::string PipelineIntegrationTestBase::GetAudioHash() {
   DCHECK(hashing_enabled_);
   return audio_sink_->GetAudioHashForTesting();
 }
 
 }  // namespace media