Disable some flaky render tests on NewTabPageTest

TBR=twellington@chromium.org

Bug: 898165
Change-Id: Id519840866ae56a2ee795ee73ba505a1a3645559
Reviewed-on: https://chromium-review.googlesource.com/c/1297057Reviewed-by: Becky Zhou <huayinz@chromium.org>
Commit-Queue: Becky Zhou <huayinz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#602091}

chrome/android/javatests/src/org/chromium/chrome/browser/ntp/NewTabPageTest.java

@@ -220,6 +220,7 @@ public class NewTabPageTest {
         scrimView.disableAnimationForTesting(false);
     }
 
+    @DisabledTest(message = "https://crbug.com/898165")
     @Test
     @SmallTest
     @Feature({"NewTabPage", "FeedNewTabPage", "RenderTest"})
@@ -230,6 +231,7 @@ public class NewTabPageTest {
         mRenderTestRule.render(mNtp.getSignInPromoViewForTesting(), "sign_in_promo");
     }
 
+    @DisabledTest(message = "https://crbug.com/898165")
     @Test
     @SmallTest
     @Feature({"NewTabPage", "FeedNewTabPage", "RenderTest"})