[Sheriff] Disable the flaky test

Disable WebViewAccessibilityTest.FocusAccessibilityNestedFrame.

TBR=dlibby@microsoft.com

Bug: 1141313
Change-Id: I2939705a8e0a9ba3c94ba131493a77b1586ed440
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2491575Reviewed-by: Hayato Ito <hayato@chromium.org>
Commit-Queue: Hayato Ito <hayato@chromium.org>
Cr-Commit-Position: refs/heads/master@{#819764}

chrome/browser/apps/guest_view/web_view_browsertest.cc

@@ -3743,8 +3743,9 @@ IN_PROC_BROWSER_TEST_F(WebViewAccessibilityTest, FocusAccessibility) {
 // focus when requested by accessibility. Previously the root
 // BrowserAccessibilityManager would not be updated due to how we were updating
 // the AXTreeData.
+// The test was disabled. See crbug.com/1141313.
 IN_PROC_BROWSER_TEST_F(WebViewAccessibilityTest,
-                       FocusAccessibilityNestedFrame) {
+                       DISABLED_FocusAccessibilityNestedFrame) {
   LoadAppWithGuest("web_view/focus_accessibility");
   content::WebContents* web_contents = GetFirstAppWindowWebContents();
   content::EnableAccessibilityForWebContents(web_contents);