Skip LayoutTests for check-webkit-style at presubmit checks

check-webkit-style internally skips LayoutTests except for TestExpectations.
This CL is for skipping that before running check-webkit-style.

Bug: none
Change-Id: Id6636d8e56c346d61e102643840baee17ecb6f9c
Reviewed-on: https://chromium-review.googlesource.com/923870Reviewed-by: Kent Tamura <tkent@chromium.org>
Commit-Queue: Makoto Shimazu <shimazu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537695}

third_party/WebKit/PRESUBMIT.py

@@ -101,10 +101,16 @@ def _CheckStyle(input_api, output_api):
     style_checker_path = input_api.os_path.join(input_api.PresubmitLocalPath(),
                                                 'Tools', 'Scripts', 'check-webkit-style')
     args = [input_api.python_executable, style_checker_path, '--diff-files']
-    files = [input_api.os_path.join('..', '..', f.LocalPath())
-             for f in input_api.AffectedFiles()
-             # Filter out files that follow Chromium's coding style.
-             if not re_chromium_style_file.search(f.LocalPath())]
+    files = []
+    for f in input_api.AffectedFiles():
+        file_path = f.LocalPath()
+        # Filter out files that follow Chromium's coding style.
+        if re_chromium_style_file.search(file_path):
+            continue
+        # Filter out changes in LayoutTests.
+        if 'LayoutTests' + input_api.os_path.sep in file_path and 'TestExpectations' not in file_path:
+            continue
+        files.append(input_api.os_path.join('..', '..', file_path))
     # Do not call check-webkit-style with empty affected file list if all
     # input_api.AffectedFiles got filtered.
     if not files:

third_party/WebKit/PRESUBMIT_test.py

@@ -41,10 +41,12 @@ class PresubmitTest(unittest.TestCase):
         """
         diff_file_webkit_h = ['some diff']
         diff_file_chromium_h = ['another diff']
+        diff_file_test_expectations = ['more diff']
         mock_input_api = MockInputApi()
         mock_input_api.files = [
             MockAffectedFile('FileWebkit.h', diff_file_webkit_h),
-            MockAffectedFile('file_chromium.h', diff_file_chromium_h)
+            MockAffectedFile('file_chromium.h', diff_file_chromium_h),
+            MockAffectedFile('LayoutTests/TestExpectations', diff_file_test_expectations)
         ]
         # Access to a protected member _CheckStyle
         # pylint: disable=W0212
@@ -52,8 +54,9 @@ class PresubmitTest(unittest.TestCase):
         capture = Capture()
         # pylint: disable=E1101
         subprocess.Popen.assert_called_with(capture, stderr=-1)
-        self.assertEqual(4, len(capture.value))
+        self.assertEqual(5, len(capture.value))
         self.assertEqual('../../FileWebkit.h', capture.value[3])
+        self.assertEqual('../../LayoutTests/TestExpectations', capture.value[4])
 
     @mock.patch('subprocess.Popen')
     def testCheckChangeOnUploadWithEmptyAffectedFileList(self, _):
@@ -62,10 +65,12 @@ class PresubmitTest(unittest.TestCase):
         """
         diff_file_chromium1_h = ['some diff']
         diff_file_chromium2_h = ['another diff']
+        diff_file_layout_test_html = ['more diff']
         mock_input_api = MockInputApi()
         mock_input_api.files = [
             MockAffectedFile('first_file_chromium.h', diff_file_chromium1_h),
-            MockAffectedFile('second_file_chromium.h', diff_file_chromium2_h)
+            MockAffectedFile('second_file_chromium.h', diff_file_chromium2_h),
+            MockAffectedFile('LayoutTests/some_tests.html', diff_file_layout_test_html)
         ]
         # Access to a protected member _CheckStyle
         # pylint: disable=W0212