Revert "[Feed] Comment out NTP asserts."

This reverts commit 068ce39e.

Reason for revert: This change is not desired on mainline.

Original change's description:
> [Feed] Comment out NTP asserts.
> 
> Bug: 992585
> Change-Id: I76d8de861d6844bfa00bd402ab8bf4110c7974f8
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1819997
> Reviewed-by: Theresa  <twellington@chromium.org>
> Commit-Queue: Sky Malice <skym@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#699099}

TBR=twellington@chromium.org,skym@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 992585
Change-Id: I43e4da44c760b324df31f48e347a1ce58b09bd7c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1828098Reviewed-by: Sky Malice <skym@chromium.org>
Commit-Queue: Sky Malice <skym@chromium.org>
Cr-Commit-Position: refs/heads/master@{#700442}

chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPage.java

@@ -9,6 +9,7 @@ import android.graphics.Canvas;
 import android.graphics.Point;
 import android.graphics.Rect;
 import android.graphics.drawable.Drawable;
+import android.support.v4.view.ViewCompat;
 import android.support.v7.widget.RecyclerView;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -697,11 +698,9 @@ public class NewTabPage implements NativePage, InvalidationAwareThumbnailProvide
 
     @Override
     public void destroy() {
-        // Temporarily removing asserts during window when they're not compiled out of release
-        // builds, see https://crbug.com/992585 for more information.
-        // assert !mIsDestroyed;
-        // assert !ViewCompat
-        //        .isAttachedToWindow(getView()) : "Destroy called before removed from window";
+        assert !mIsDestroyed;
+        assert !ViewCompat
+                .isAttachedToWindow(getView()) : "Destroy called before removed from window";
         if (mIsLoaded && !mTab.isHidden()) recordNTPHidden();
 
         mNewTabPageManager.onDestroy();