Add file permissions to filesystem_mock

third_party/WebKit/Tools/Scripts/webkitpy/common/system/filesystem_mock_unittest.py

Index: third_party/WebKit/Tools/Scripts/webkitpy/common/system/filesystem_mock_unittest.py
diff --git a/third_party/WebKit/Tools/Scripts/webkitpy/common/system/filesystem_mock_unittest.py b/third_party/WebKit/Tools/Scripts/webkitpy/common/system/filesystem_mock_unittest.py
index 42d83c0a516dd38bc64e3c377de012bf2e1e7aa7..f0a6b1bf587726c5e3a12ed8f562e1054a34a669 100644
--- a/third_party/WebKit/Tools/Scripts/webkitpy/common/system/filesystem_mock_unittest.py
+++ b/third_party/WebKit/Tools/Scripts/webkitpy/common/system/filesystem_mock_unittest.py
@@ -111,3 +111,11 @@ class MockFileSystemTest(unittest.TestCase, filesystem_unittest.GenericFileSyste
                                                            ('foo/a', ['z'], ['x', 'y']),
                                                            ('foo/a/z', [], ['lyrics']),
                                                            ('foo/bar', [], ['quux', 'baz'])])
+
+    def test_executable(self):
+        host = MockHost()
+        mock_files = {'foo': '', 'bar': ''}
+        host.filesystem = MockFileSystem(files=mock_files)
+        host.filesystem.executable_files.add('bar')
+        host.filesystem.make_executable('bar', 'foo')
+        self.assertEquals(host.filesystem.is_executable('foo'), True)