Disable NavigationAccessibilityTest.TestNavigateToNewUrl due to flakes.

BUG=791981
TBR=dmazzoni@chromium.org
NOTRY=true

Change-Id: I325920f109ae515a43eef3fcd10760e736e4114d
Reviewed-on: https://chromium-review.googlesource.com/808705Reviewed-by: Greg Thompson <grt@chromium.org>
Commit-Queue: Greg Thompson <grt@chromium.org>
Cr-Commit-Position: refs/heads/master@{#521681}

chrome/browser/ui/views/accessibility/navigation_accessibility_uitest_win.cc

@@ -203,7 +203,10 @@ class NavigationAccessibilityTest : public InProcessBrowserTest {
 
 // Tests that when focus is in the omnibox and the user types a url and
 // presses enter, no focus events are sent on the old document.
-IN_PROC_BROWSER_TEST_F(NavigationAccessibilityTest, TestNavigateToNewUrl) {
+// Disabled due to flaky CHECK failures in
+// WinAccessibilityEventMonitor::WaitForNextEvent; see https://crbug.com/791981.
+IN_PROC_BROWSER_TEST_F(NavigationAccessibilityTest,
+                       DISABLED_TestNavigateToNewUrl) {
   content::BrowserAccessibilityState::GetInstance()->EnableAccessibility();
 
   ui_test_utils::NavigateToURL(browser(),