[Sheriff] Disable MixedContentSettingsWithBlockingCSP on Win Dbg

Test times out on Windows debug bot.

Bug: 890372
Change-Id: Ib337d19167c8864612bf697b2adb420507c27e76
Tbr: cthomp@chromium.org, estark@chromium.org
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1585536Reviewed-by: Adithya Srinivasan <adithyas@chromium.org>
Commit-Queue: Adithya Srinivasan <adithyas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#654574}

chrome/browser/ssl/ssl_browsertest.cc

@@ -4082,8 +4082,15 @@ IN_PROC_BROWSER_TEST_P(SSLUIWorkerFetchTest,
 // blocked regardless of the settings in WebPreferences when
 // block-all-mixed-content CSP is set.
 // TODO(crbug.com/890372): This test is flaky.
+#if defined(OS_WIN) && !defined(NDEBUG)
+#define MAYBE_MixedContentSettingsWithBlockingCSP \
+  DISABLED_MixedContentSettingsWithBlockingCSP
+#else
+#define MAYBE_MixedContentSettingsWithBlockingCSP \
+  MixedContentSettingsWithBlockingCSP
+#endif
 IN_PROC_BROWSER_TEST_P(SSLUIWorkerFetchTest,
-                       MixedContentSettingsWithBlockingCSP) {
+                       MAYBE_MixedContentSettingsWithBlockingCSP) {
   ChromeContentBrowserClientForMixedContentTest browser_client;
   content::ContentBrowserClient* old_browser_client =
       content::SetBrowserClientForTesting(&browser_client);