Mark BottomSheetControllerTest#testSwitchTabsMultipleTimes as flaky

The test fails pretty consistently on Android M

TBR=mdjones@chromium.org

Bug: 837809
Change-Id: I1a1ac99ce0f501afa310f339431673bbc607efa5
Reviewed-on: https://chromium-review.googlesource.com/1072472Reviewed-by: Alexandr Ilin <alexilin@chromium.org>
Commit-Queue: Alexandr Ilin <alexilin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#561887}

chrome/android/javatests/src/org/chromium/chrome/browser/widget/bottomsheet/BottomSheetControllerTest.java

@@ -20,6 +20,7 @@ import org.chromium.base.ThreadUtils;
 import org.chromium.base.test.util.CallbackHelper;
 import org.chromium.base.test.util.CommandLineFlags;
 import org.chromium.base.test.util.Feature;
+import org.chromium.base.test.util.FlakyTest;
 import org.chromium.base.test.util.Restriction;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.ChromeSwitches;
@@ -188,6 +189,7 @@ public class BottomSheetControllerTest {
     }
 
     @Test
+    @FlakyTest(message = "https://crbug.com/837809")
     @MediumTest
     @Feature({"BottomSheetController"})
     public void testSwitchTabsMultipleTimes() throws InterruptedException, TimeoutException {