Disable flaky testNavigationCallbacks test.

Bug: 842929
Change-Id: I2e4f67cd3ae1620f6c4cb6fdfeb2a99139168f04
Tbr: mvanouwerkerk@chromium.org
Tbr: tedchoc@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/1060119Reviewed-by: Ted Choc <tedchoc@chromium.org>
Reviewed-by: Łukasz Anforowicz <lukasza@chromium.org>
Commit-Queue: Łukasz Anforowicz <lukasza@chromium.org>
Cr-Commit-Position: refs/heads/master@{#558839}

chrome/android/javatests/src/org/chromium/chrome/browser/webapps/TrustedWebActivityTest.java

@@ -27,6 +27,7 @@ import org.junit.runner.RunWith;
 
 import org.chromium.base.test.util.CallbackHelper;
 import org.chromium.base.test.util.CommandLineFlags;
+import org.chromium.base.test.util.DisabledTest;
 import org.chromium.base.test.util.Feature;
 import org.chromium.chrome.browser.ChromeSwitches;
 import org.chromium.chrome.browser.ShortcutHelper;
@@ -83,6 +84,7 @@ public class TrustedWebActivityTest {
     @Test
     @SmallTest
     @Feature({"Webapps"})
+    @DisabledTest // TODO(https://crbug.com/842929): Re-enable after unflaking.
     public void testNavigationCallbacks() throws Exception {
         final CallbackHelper startedCallback = new CallbackHelper();
         final CallbackHelper finishedCallback = new CallbackHelper();