Disables CaptureModeTest.VideoRecordingUiBehavior as it's flakey

BUG=1141927
TEST=test only change
TBR=xdai@chromium.org

Change-Id: I150f47081d1d88afc15c0c90f7f1fc6c333aee48
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2495831Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Xiaoqian Dai <xdai@chromium.org>
Commit-Queue: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#820461}

ash/capture_mode/capture_mode_unittests.cc

@@ -287,7 +287,8 @@ TEST_F(CaptureModeTest, ChangeTypeAndSourceFromUI) {
   EXPECT_EQ(controller->source(), CaptureModeSource::kFullscreen);
 }
 
-TEST_F(CaptureModeTest, VideoRecordingUiBehavior) {
+// TODO(https://crbug.com/1141927): test is flakey.
+TEST_F(CaptureModeTest, DISABLED_VideoRecordingUiBehavior) {
   // We need a non-zero duration to avoid infinite loop on countdown.
   ui::ScopedAnimationDurationScaleMode animatin_scale(
       ui::ScopedAnimationDurationScaleMode::NON_ZERO_DURATION);