Remove webui_polymer2_browser_tests from Win 10 Tests x64 (dbg) bot

These tests are timing out periodically. Match the removal of
browser_tests, since the behavior is expected to be the same.

Bug: 876224
Change-Id: I76183e78fde8f10a1feae67db51ca4336a4c652e
Reviewed-on: https://chromium-review.googlesource.com/1197322
Reviewed-by: John Budorick <[email protected]>
Commit-Queue: Rebekah Potter <[email protected]>
Cr-Commit-Position: refs/heads/master@{#587675}
diff --git a/testing/buildbot/test_suite_exceptions.pyl b/testing/buildbot/test_suite_exceptions.pyl
index 0434ceb..6270e31 100644
--- a/testing/buildbot/test_suite_exceptions.pyl
+++ b/testing/buildbot/test_suite_exceptions.pyl
@@ -1707,6 +1707,12 @@
       },
     },
   },
+  'webui_polymer2_browser_tests': {
+    'remove_from': [
+      # chromium.win
+      'Win10 Tests x64 (dbg)',  # Matches browser_tests.
+    ],
+  },
   'webui_polymer2_interactive_ui_tests': {
     'modifications': {
       # Match interactive_ui_tests, see https://crbug.com/840369