Really fix build after r193020.

content/test/layout_browsertest.cc

Index: content/test/layout_browsertest.cc
diff --git a/content/test/layout_browsertest.cc b/content/test/layout_browsertest.cc
index 155dbbe27b695d84c0ecd31cb79ba6768a9ede14..431e890a06c6b6ad1d8c0b2397f851ad1bf66205 100644
--- a/content/test/layout_browsertest.cc
+++ b/content/test/layout_browsertest.cc
@@ -196,7 +196,7 @@ std::string InProcessBrowserLayoutTest::SaveResults(const std::string& expected,
                                                     const std::string& actual) {
   base::FilePath cwd;
   EXPECT_TRUE(file_util::CreateNewTempDirectory(
-      FILE_PATH_LITERAL(std::string()), &cwd));
+      base::FilePath::StringType(), &cwd));
   base::FilePath expected_filename =
       cwd.Append(FILE_PATH_LITERAL("expected.txt"));
   base::FilePath actual_filename = cwd.Append(FILE_PATH_LITERAL("actual.txt"));