Fix base::GetNativeLibraryName() for Mac.

base/profiler/stack_sampling_profiler_unittest.cc

Index: base/profiler/stack_sampling_profiler_unittest.cc
diff --git a/base/profiler/stack_sampling_profiler_unittest.cc b/base/profiler/stack_sampling_profiler_unittest.cc
index 9a644c3e2105bb27bdbce095175387d0d999ff98..3c7bf69d01d2e0953595eaef26f440fba1db0ae3 100644
--- a/base/profiler/stack_sampling_profiler_unittest.cc
+++ b/base/profiler/stack_sampling_profiler_unittest.cc
@@ -271,9 +271,8 @@ NativeLibrary LoadOtherLibrary() {
   const auto load = [](NativeLibrary* library) {
     FilePath other_library_path;
     ASSERT_TRUE(PathService::Get(DIR_EXE, &other_library_path));
-    other_library_path = other_library_path.Append(FilePath::FromUTF16Unsafe(
-        GetNativeLibraryName(ASCIIToUTF16(
-            "base_profiler_test_support_library"))));
+    other_library_path = other_library_path.AppendASCII(
+        GetNativeLibraryName("base_profiler_test_support_library"));
     NativeLibraryLoadError load_error;
     *library = LoadNativeLibrary(other_library_path, &load_error);
     ASSERT_TRUE(*library) << "error loading " << other_library_path.value()