Sheriff: Disable ChromeVoxBackgroundTest.NavigationSyncsSelect

This test was failing on https://ci.chromium.org/p/chromium/builders/ci/Linux%20ChromiumOS%20MSan%20Tests/13544

TBR=akihiroota@chromium.org,aboxhall@chromium.org

Bug: 976105
Change-Id: I52a6f9a792d7e47acc5caff9143529333221e33c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1666440
Commit-Queue: Darwin Huang <huangdarwin@chromium.org>
Reviewed-by: Darwin Huang <huangdarwin@chromium.org>
Reviewed-by: Akihiro Ota <akihiroota@chromium.org>
Cr-Commit-Position: refs/heads/master@{#670345}

chrome/browser/resources/chromeos/chromevox/cvox2/background/background_test.extjs

@@ -1551,7 +1551,7 @@ TEST_F('ChromeVoxBackgroundTest', 'NavigationEscapesEdit', function() {
   });
 });
 
-TEST_F('ChromeVoxBackgroundTest', 'NavigationSyncsSelect', function() {
+TEST_F('ChromeVoxBackgroundTest', 'DISABLED_NavigationSyncsSelect', function() {
   var mockFeedback = this.createMockFeedback();
   this.runWithLoadedTree(function() {/*!
     <select>