Fix memory leak in logging-unittest.

test/unittests/base/logging-unittest.cc

 // Copyright 2015 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 <cstdint>
 
 #include "src/base/logging.h"
 #include "src/objects.h"
 #include "testing/gtest-support.h"
 
 namespace v8 {
 namespace base {
 
 namespace {
 
 #define CHECK_SUCCEED(NAME, lhs, rhs)                                      \
   {                                                                        \
     std::string* error_message =                                           \
         Check##NAME##Impl<decltype(lhs), decltype(rhs)>((lhs), (rhs), ""); \
     EXPECT_EQ(nullptr, error_message);                                     \
   }
 
 #define CHECK_FAIL(NAME, lhs, rhs)                                         \
   {                                                                        \
     std::string* error_message =                                           \
         Check##NAME##Impl<decltype(lhs), decltype(rhs)>((lhs), (rhs), ""); \
     EXPECT_NE(nullptr, error_message);                                     \
+    delete error_message;                                                  \
   }
 
 }  // namespace
 
 TEST(LoggingTest, CheckEQImpl) {
   CHECK_SUCCEED(EQ, 0.0, 0.0)
   CHECK_SUCCEED(EQ, 0.0, -0.0)
   CHECK_SUCCEED(EQ, -0.0, 0.0)
   CHECK_SUCCEED(EQ, -0.0, -0.0)
 }
@@ skipping 19 matching lines @@
 }
 
 TEST(LoggingTest, CompareAgainstStaticConstPointer) {
   // These used to produce link errors before http://crrev.com/2524093002.
   CHECK_FAIL(EQ, v8::internal::Smi::kZero, v8::internal::Smi::FromInt(17));
   CHECK_SUCCEED(GT, 0, v8::internal::Smi::kMinValue);
 }
 
 }  // namespace base
 }  // namespace v8