Use FilePath::DirName instead of the deprecated file_util::GetDirectoryFromPath.

base/file_util_unittest.cc

Index: base/file_util_unittest.cc
diff --git a/base/file_util_unittest.cc b/base/file_util_unittest.cc
index fa00fcf92c2426c7a409c0172791c486bc05150e..bbd888ace1a0512caee40221f0f49cd504b4193d 100644
--- a/base/file_util_unittest.cc
+++ b/base/file_util_unittest.cc
@@ -315,18 +315,6 @@ static const struct dir_case {
 #endif
 };
 
-#if defined(OS_WIN)
-// This function is deprecated, and only exists on Windows anymore.
-TEST_F(FileUtilTest, GetDirectoryFromPath) {
-  for (unsigned int i = 0; i < arraysize(dir_cases); ++i) {
-    const dir_case& dir = dir_cases[i];
-    const std::wstring parent =
-        file_util::GetDirectoryFromPath(dir.full_path);
-    EXPECT_EQ(dir.directory, parent);
-  }
-}
-#endif
-
 // Flaky, http://crbug.com/46246
 TEST_F(FileUtilTest, FLAKY_CountFilesCreatedAfter) {
   // Create old file (that we don't want to count)