Disable core.stacktrace_unittest.TabStackTraceTest.testValidDump on win

TBR=kbr@chromium.org
NOTRY=true  # net_unittests flake

Bug: 846289
Change-Id: I7fa42786ebdb448fd424e37a7c777e60df6b3c36
Reviewed-on: https://chromium-review.googlesource.com/1071868
Commit-Queue: Ned Nguyen <nednguyen@google.com>
Reviewed-by: Ned Nguyen <nednguyen@google.com>
Cr-Commit-Position: refs/heads/master@{#561594}

tools/perf/core/stacktrace_unittest.py

@@ -16,6 +16,7 @@ class TabStackTraceTest(tab_test_case.TabTestCase):
   # disabled shortly so just disable it for now.
   # All platforms except chromeos should at least have a valid minidump.
   @decorators.Disabled('snowleopard', 'chromeos')
+  @decorators.Disabled('win')  # crbug.com/846289
   def testValidDump(self):
     with self.assertRaises(exceptions.DevtoolsTargetCrashException) as c:
       self._tab.Navigate('chrome://crash', timeout=5)