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

gpu/command_buffer/service/program_manager.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 "gpu/command_buffer/service/program_manager.h"
 
 #include <algorithm>
 #include <set>
 #include <utility>
 #include <vector>
@@ skipping 427 matching lines @@
     if (mapped_name && *mapped_name != it->first)
       glBindAttribLocation(service_id_, it->second, mapped_name->c_str());
   }
 }
 
 void ProgramManager::DoCompileShader(Shader* shader,
                                      ShaderTranslator* translator,
                                      FeatureInfo* feature_info) {
   TimeTicks before = TimeTicks::HighResNow();
   if (program_cache_ &&
-      program_cache_->GetShaderCompilationStatus(shader->source() ?
-                                                 *shader->source() : "") ==
+      program_cache_->GetShaderCompilationStatus(
+          shader->source() ? *shader->source() : std::string()) ==
           ProgramCache::COMPILATION_SUCCEEDED) {
     shader->SetStatus(true, "", translator);
     shader->FlagSourceAsCompiled(false);
     UMA_HISTOGRAM_CUSTOM_COUNTS(
         "GPU.ProgramCache.CompilationCacheHitTime",
         (TimeTicks::HighResNow() - before).InMicroseconds(),
         0,
         TimeDelta::FromSeconds(1).InMicroseconds(),
         50);
     return;
@@ skipping 58 matching lines @@
     glGetShaderiv(shader->service_id(), GL_INFO_LOG_LENGTH, &max_len);
     scoped_ptr<char[]> temp(new char[max_len]);
     GLint len = 0;
     glGetShaderInfoLog(shader->service_id(), max_len, &len, temp.get());
     DCHECK(max_len == 0 || len < max_len);
     DCHECK(len == 0 || temp[len] == '\0');
     shader->SetStatus(false, std::string(temp.get(), len).c_str(), NULL);
     LOG_IF(ERROR, translator)
         << "Shader translator allowed/produced an invalid shader "
         << "unless the driver is buggy:"
-        << "\n--original-shader--\n" << (source ? *source : "")
-        << "\n--translated-shader--\n" << shader_src
-        << "\n--info-log--\n" << *shader->log_info();
+        << "\n--original-shader--\n" << (source ? *source : std::string())
+        << "\n--translated-shader--\n" << shader_src << "\n--info-log--\n"
+        << *shader->log_info();
   }
 }
 
 bool Program::Link(ShaderManager* manager,
                    ShaderTranslator* vertex_translator,
                    ShaderTranslator* fragment_translator,
                    FeatureInfo* feature_info,
                    const ShaderCacheCallback& shader_callback) {
   ClearLinkStatus();
   if (!CanLink()) {
@@ skipping 681 matching lines @@
     program->ClearUniforms(&zero_);
   }
 }
 
 int32 ProgramManager::MakeFakeLocation(int32 index, int32 element) {
   return index + element * 0x10000;
 }
 
 }  // namespace gles2
 }  // namespace gpu