dbus/values_util_unittest.cc: use sqrt from cmath

dbus/values_util_unittest.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 "dbus/values_util.h"
 
+#include <cmath>
 #include <vector>
 
 #include "base/json/json_writer.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/values.h"
 #include "dbus/message.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace dbus {
 
@@ skipping 333 matching lines @@
   ASSERT_TRUE(value.get() != NULL);
   EXPECT_TRUE(value->Equals(&dictionary_value));
 }
 
 TEST(ValuesUtilTest, PopDoubleToIntDictionary) {
   // Create test data.
   const int32 kValues[] = {0, 1, 1, 2, 3, 5, 8, 13, 21};
   const std::vector<int32> values(kValues, kValues + arraysize(kValues));
   std::vector<double> keys(values.size());
   for (size_t i = 0; i != values.size(); ++i)
-    keys[i] = sqrt(values[i]);
+    keys[i] = std::sqrt(values[i]);
 
   // Append a dictionary.
   scoped_ptr<Response> response(Response::CreateEmpty());
   MessageWriter writer(response.get());
   MessageWriter sub_writer(NULL);
   writer.OpenArray("{di}", &sub_writer);
   for (size_t i = 0; i != values.size(); ++i) {
     MessageWriter entry_writer(NULL);
     sub_writer.OpenDictEntry(&entry_writer);
     entry_writer.AppendDouble(keys[i]);
@@ skipping 309 matching lines @@
   scoped_ptr<base::Value> value;
   value.reset(PopDataAsValue(&reader));
   ASSERT_TRUE(value.get() != NULL);
   EXPECT_TRUE(value->Equals(&test_list));
   value.reset(PopDataAsValue(&reader));
   ASSERT_TRUE(value.get() != NULL);
   EXPECT_TRUE(value->Equals(&int_value));
 }
 
 }  // namespace dbus