[Instant Start] Re-enable testShow_SingleAsHomepage_NoMVTiles.

Bug: 1103838, 1092642, 1076274
Change-Id: Ia44be7834b698bd37f0d6bd80de31257ea38eecf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2325249Reviewed-by: Wei-Yin Chen (陳威尹) <wychen@chromium.org>
Commit-Queue: Xi Han <hanxi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#796359}

chrome/android/features/start_surface/internal/javatests/src/org/chromium/chrome/features/start_surface/StartSurfaceTest.java

@@ -474,11 +474,6 @@ public class StartSurfaceTest {
             fail("Failed to tap 'more tabs' " + e.toString());
         }
         onViewWaiting(withId(R.id.secondary_tasks_surface_view));
-        if (isInstantReturn()) {
-            // TODO(crbug.com/1076274): fix toolbar to avoid wrongly focusing on the toolbar
-            // omnibox.
-            return;
-        }
 
         pressBack();
         onViewWaiting(withId(R.id.primary_tasks_surface_view));