Add skia_test_expectations file; see https://bugs.webkit.org/show_bug.cgi?id=86749

skia/skia_test_expectations.txt

+// TEMPORARY overrides of
+// src/third_party/WebKit/LayoutTests/platform/chromium/test_expectations.txt
+// that are associated with changes to the Skia code.
+//
+// GUIDELINES:
+// - This file should be empty most of the time.
+// - Expectations should only be added TEMPORARILY, as a step towards
+//   rebaselining layout test results.  If any one expectation remains in here
+//   for more than a week or two, then we are probably doing something wrong.
+// - Expectations from this file should NOT be rolled into any other
+//   test_expectations file.  If there is a test that we expect to fail
+//   indefinitely, then we should add that test to the roach motel that is
+//   src/third_party/WebKit/LayoutTests/platform/chromium/test_expectations.txt
+// - Tests listed in this file should NOT be rebaselined by WebKit Gardeners,
+//   unless they have made arrangements with Skia developers.
+//
+// For more information, see https://bugs.webkit.org/show_bug.cgi?id=86749
+// or email skia-dev@google.com .
+//
+// INSTRUCTIONS:
+// If you are rolling Skia's DEPS within Chrome, and trybot results indicate
+// that the DEPS roll would break some webkit layout_tests, please follow
+// these steps:
+//
+// 1. Confirm that those layout_test failures are "reasonable"-- Are they
+// actually improvements, not regressions?  Or maybe they are very minor
+// differences that go along with a performance improvement?
+// If not, please fix Skia rather than rolling in the version that will
+// regress the webkit layout_tests.
+//
+// 2. File a bug to yourself to track the rebaselining of results caused by
+// your Skia DEPS roll.
+//
+// 3. Add one or more lines to this file, in the same syntax used in the main
+// test_expectations file, to mark those tests as expected-to-fail.
+// Add this file to your DEPS roll CL.
+//
+// 4. Run your DEPS roll CL through the trybots again, and confirm your CL does
+// not cause any layout tests to fail.  (If there are still failures as a
+// result of your CL, you probably didn't add the test expectations correctly.)
+//
+// 5. Commit your DEPS roll CL, and keep an eye on the waterfall bots to make
+// sure nothing goes red.
+//
+// 6. Make sure to rebaseline the layout tests as soon as possible!  The longer
+// we leave overrides in this file, the harder it will be to rebaseline those
+// tests (because other rendering changes might creep in).
+//
+// START OVERRIDES HERE
+
+
+// END OVERRIDES HERE (this line ensures that the file is newline-terminated)