Replace OStream with std::ostream.

src/compiler/graph-unittest.cc

 // Copyright 2014 the V8 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.
 
 #include "src/compiler/graph-unittest.h"
 
 #include <ostream>  // NOLINT(readability/streams)
 
 #include "src/compiler/node-properties-inl.h"
 
 using testing::_;
 using testing::MakeMatcher;
 using testing::MatcherInterface;
 using testing::MatchResultListener;
 using testing::StringMatchResultListener;
 
 namespace v8 {
 namespace internal {
 
 // TODO(bmeurer): Find a new home for these functions.
 template <typename T>
 inline std::ostream& operator<<(std::ostream& os, const Unique<T>& value) {
   return os << *value.handle();
 }
 inline std::ostream& operator<<(std::ostream& os,
                                 const ExternalReference& value) {
-  OStringStream ost;
-  compiler::StaticParameterTraits<ExternalReference>::PrintTo(ost, value);
-  return os << ost.c_str();
+  compiler::StaticParameterTraits<ExternalReference>::PrintTo(os, value);
+  return os;
 }
 
 namespace compiler {
 
 GraphTest::GraphTest(int num_parameters) : common_(zone()), graph_(zone()) {
   graph()->SetStart(graph()->NewNode(common()->Start(num_parameters)));
 }
 
 
 GraphTest::~GraphTest() {}
@@ skipping 732 matching lines @@
 IS_UNOP_MATCHER(ChangeUint32ToUint64)
 IS_UNOP_MATCHER(TruncateFloat64ToFloat32)
 IS_UNOP_MATCHER(TruncateFloat64ToInt32)
 IS_UNOP_MATCHER(TruncateInt64ToInt32)
 IS_UNOP_MATCHER(Float64Sqrt)
 #undef IS_UNOP_MATCHER
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8