Add expectations/gm/ignored-tests.txt to temporarily ignore failures

expectations/gm/ignored-tests.txt

+# Failures of any GM tests listed in this file will be ignored, as if they

[epoger, 2013/09/19 15:02:52]

The buildbots don't know to look for this file yet... I'm working on that in a
separate CL.

[epoger, 2013/09/19 16:13:44]

... and that separate CL is https://codereview.chromium.org/24283002/
('GenerateGMs step on buildots: pass --ignoreTests arguments into gm')

+# had been marked "ignore-failure": true in the per-builder
+# expected-results.json files.
+#
+# The idea is that, if you modify a GM test in such a way that you know it will
+# require rebaselines on multiple platforms, you should add that test's name to
+# this list within the same CL that modifies the test.
+# Then, AS SOON AS POSSIBLE, you should rebaseline the tests (they will show up
+# as status "failure-ignored") and remove the line you added to this file.
+# If there are any lingering failures that need to be suppressed (ignored), you
+# MUST move those suppressions into the per-builder expected-results.json files.
+#
+# Any lines starting with '#' are comments and will be ignored.
+# Other than that, each line must either be whitespace or list just one test.
+#
+# For more information, see https://code.google.com/p/skia/issues/detail?id=1600
+# ('GM expectations: create tool to suppress failures until new baselines are
+# checked in')
+
+# EXAMPLE: (remove the first '#' on each line)
+## Added by edisonn as part of https://codereview.chromium.org/23851037/
+#gradients