Revert "Disable core.stacktrace_unittest.TabStackTraceTest.testValidDump on win"

This reverts commit 216e6d16.

Reason for revert: culrpit CL was reverted 

BUG:chromium:846313

Original change's description:
> 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}

TBR=nednguyen@google.com

Change-Id: Ibf328d3ea480b094e47c5037a7498f198ef94e62
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 846289
Reviewed-on: https://chromium-review.googlesource.com/1073091
Commit-Queue: Ned Nguyen <nednguyen@google.com>
Reviewed-by: Ned Nguyen <nednguyen@google.com>
Cr-Commit-Position: refs/heads/master@{#561881}

tools/perf/core/stacktrace_unittest.py

@@ -16,7 +16,6 @@ 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/846313
   def testValidDump(self):
     with self.assertRaises(exceptions.DevtoolsTargetCrashException) as c:
       self._tab.Navigate('chrome://crash', timeout=5)