[Sheriff] Disable SSLUITestIgnoreCertErrors.SubframeHasCertError

Flake Portal:
https://analysis.chromium.org/p/chromium/flake-portal/flakes/occurrences?key=ag9zfmZpbmRpdC1mb3ItbWVyUAsSBUZsYWtlIkVjaHJvbWl1bUBicm93c2VyX3Rlc3RzQFNTTFVJVGVzdElnbm9yZUNlcnRFcnJvcnMuU3ViZnJhbWVIYXNDZXJ0RXJyb3IM

TBR=estark@chromium.org

Bug: 1106370
Change-Id: Ibee02ba23881f78b28c27e3652ccbf60fa7a6f86
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2303055Reviewed-by: Sahel Sharify <sahel@chromium.org>
Commit-Queue: Sahel Sharify <sahel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#789264}

chrome/browser/ssl/ssl_browsertest.cc

@@ -1098,7 +1098,8 @@ IN_PROC_BROWSER_TEST_F(SSLUITest, TestBrokenHTTPSWithActiveInsecureContent) {
 
 // Tests that when a subframe commits a main resource with a certificate error,
 // the navigation entry is marked as insecure.
-IN_PROC_BROWSER_TEST_F(SSLUITestIgnoreCertErrors, SubframeHasCertError) {
+// Flaky. See https://crbug.com/1106370.
+IN_PROC_BROWSER_TEST_F(SSLUITestIgnoreCertErrors, DISABLED_SubframeHasCertError) {
   ASSERT_TRUE(https_server_mismatched_.Start());
   // Load a page with a data: favicon URL to suppress a favicon request. A
   // favicon request can cause the navigation entry to get marked as having run