Re-enable NewTabPageTest#testRender_ArticleSectionHeader

Test succeeded 10/10 times locally on an emulator M tablet, so
re-enabling to see if it's still flaky on bots. Increasing timeout to
MediumTest either way since this is more than a simple unit test.

Bug: 945293
Change-Id: I3d82eac071af9de75dae88dc2e60b3fe40892a7b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2134612
Commit-Queue: Natalie Chouinard <chouinard@chromium.org>
Reviewed-by: Theresa  <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#756294}

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

@@ -238,9 +238,8 @@ public class NewTabPageTest {
         mRenderTestRule.render(mNtp.getSignInPromoViewForTesting(), "sign_in_promo");
     }
 
-    @DisabledTest(message = "https://crbug.com/945293")
     @Test
-    @SmallTest
+    @MediumTest
     @Feature({"NewTabPage", "FeedNewTabPage", "RenderTest"})
     @ParameterAnnotations.UseMethodParameter(InterestFeedParams.class)
     public void testRender_ArticleSectionHeader(boolean interestFeedEnabled) throws Exception {

chrome/test/data/android/render_tests/NewTabPageTest.expandable_header_collapsed.Nexus_5X-23.png.sha1

+e56d2a4dbd8a8a78c5c6cb8ea5428588cffe1332
\ No newline at end of file

chrome/test/data/android/render_tests/NewTabPageTest.expandable_header_expanded.Nexus_5X-23.png.sha1

+8ef5fc962c9a6447b5fe004c299e5c2b3e4d6112
\ No newline at end of file