Convert //chrome/browser/chromeos from scoped_ptr to std::unique_ptr

chrome/browser/chromeos/login/signin/device_id_browsertest.cc

Index: chrome/browser/chromeos/login/signin/device_id_browsertest.cc
diff --git a/chrome/browser/chromeos/login/signin/device_id_browsertest.cc b/chrome/browser/chromeos/login/signin/device_id_browsertest.cc
index 9f048538847979c1aaf0c8139780d4ed8d7d0bfc..4934033ee1cddc7a011282812a9a3b98a5aa8253 100644
--- a/chrome/browser/chromeos/login/signin/device_id_browsertest.cc
+++ b/chrome/browser/chromeos/login/signin/device_id_browsertest.cc
@@ -146,7 +146,7 @@ class DeviceIDTest : public OobeBaseTest,
     if (!base::ReadFileToString(GetRefreshTokenToDeviceIdMapFilePath(),
                                 &file_contents))
       return;
-    scoped_ptr<base::Value> value(base::JSONReader::Read(file_contents));
+    std::unique_ptr<base::Value> value(base::JSONReader::Read(file_contents));
     base::DictionaryValue* dictionary;
     EXPECT_TRUE(value->GetAsDictionary(&dictionary));
     FakeGaia::RefreshTokenToDeviceIdMap map;