Disable flaky SelectToSpeakTest.FocusRingMovesWithMouse test

BUG=950049
TBR=nektar@chromium.org,avi@chromium.org

Change-Id: I07d3e741c02eeae93be6d9c2647aedad4a735ebe
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1555000Reviewed-by: Alexei Filippov <alph@chromium.org>
Commit-Queue: Alexei Filippov <alph@chromium.org>
Cr-Commit-Position: refs/heads/master@{#648278}

chrome/browser/chromeos/accessibility/select_to_speak_browsertest.cc

@@ -281,7 +281,8 @@ IN_PROC_BROWSER_TEST_F(SelectToSpeakTest, BreaksAtParagraphBounds) {
                                  "Second paragraph*"));
 }
 
-IN_PROC_BROWSER_TEST_F(SelectToSpeakTest, FocusRingMovesWithMouse) {
+// Flaky test. https://crbug.com/950049
+IN_PROC_BROWSER_TEST_F(SelectToSpeakTest, DISABLED_FocusRingMovesWithMouse) {
   // Create a callback for the focus ring observer.
   base::RepeatingCallback<void()> callback =
       base::BindRepeating(&SelectToSpeakTest::OnFocusRingChanged, GetWeakPtr());