[NTP Client][Reland]Spacing and fixes for the sign in promo

chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/NewTabPageAdapter.java

Index: chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/NewTabPageAdapter.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/NewTabPageAdapter.java b/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/NewTabPageAdapter.java
index 61c9993dbb1cee56ddc4a72b658f488d7ba09acb..8b42f012f91ad944a4e2f45c9d7c1bd0ee8de6f8 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/NewTabPageAdapter.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/NewTabPageAdapter.java
@@ -69,7 +69,7 @@ public class NewTabPageAdapter extends Adapter<NewTabPageViewHolder>
     private class ItemTouchCallbacks extends ItemTouchHelper.Callback {
         @Override
         public void onSwiped(ViewHolder viewHolder, int direction) {
-            mRecyclerView.onItemDismissStarted(viewHolder.itemView);
+            mRecyclerView.onItemDismissStarted(viewHolder);
             NewTabPageAdapter.this.dismissItem(viewHolder.getAdapterPosition());
         }
 
@@ -79,7 +79,7 @@ public class NewTabPageAdapter extends Adapter<NewTabPageViewHolder>
             // not mean that the user went all the way and dismissed the item before releasing it.
             // We need to check that the item has been removed.
             if (viewHolder.getAdapterPosition() == RecyclerView.NO_POSITION) {
-                mRecyclerView.onItemDismissFinished(viewHolder.itemView);
+                mRecyclerView.onItemDismissFinished(viewHolder);
             }
 
             super.clearView(recyclerView, viewHolder);
@@ -364,10 +364,10 @@ public class NewTabPageAdapter extends Adapter<NewTabPageViewHolder>
     }
 
     public int getFirstCardPosition() {
-        // TODO(mvanouwerkerk): Don't rely on getFirstHeaderPosition() here.
-        int firstHeaderPosition = getFirstHeaderPosition();
-        if (firstHeaderPosition == RecyclerView.NO_POSITION) return RecyclerView.NO_POSITION;
-        return firstHeaderPosition + 1;
+        for (int i = 0; i < getItemCount(); ++i) {
+            if (CardViewHolder.isCard(getItemViewType(i))) return i;
+        }
+        return RecyclerView.NO_POSITION;
     }
 
     public int getLastContentItemPosition() {
@@ -413,7 +413,7 @@ public class NewTabPageAdapter extends Adapter<NewTabPageViewHolder>
         mGroups.add(mAboveTheFold);
         mGroups.addAll(mSections.values());
         mGroups.add(mSigninPromo);
-        if (!mSections.isEmpty()) {
+        if (hasVisibleBelowTheFoldItems()) {
             mGroups.add(mFooter);
             mGroups.add(mBottomSpacer);
         }
@@ -429,7 +429,7 @@ public class NewTabPageAdapter extends Adapter<NewTabPageViewHolder>
 
         notifyItemRangeRemoved(startPos, removedItems);
 
-        if (mSections.isEmpty()) {
+        if (!hasVisibleBelowTheFoldItems()) {
             mGroups.remove(mFooter);
             mGroups.remove(mBottomSpacer);
             notifyItemRangeRemoved(startPos + removedItems, 2);
@@ -555,6 +555,13 @@ public class NewTabPageAdapter extends Adapter<NewTabPageViewHolder>
     private void dismissPromo() {
         // TODO(dgn): accessibility announcement.
         mSigninPromo.dismiss();
+
+        if (!hasVisibleBelowTheFoldItems()) {
+            int footerPosition = getLastContentItemPosition();
+            mGroups.remove(mFooter);
+            mGroups.remove(mBottomSpacer);
+            notifyItemRangeRemoved(footerPosition, 2);
+        }
     }
 
     /**
@@ -569,9 +576,9 @@ public class NewTabPageAdapter extends Adapter<NewTabPageViewHolder>
     }
 
     /**
-     * Returns another view holder that should be dismissed as the same time as the provided one.
+     * Returns another view holder that should be dismissed at the same time as the provided one.
      */
-    private ViewHolder getDismissSibling(ViewHolder viewHolder) {
+    public ViewHolder getDismissSibling(ViewHolder viewHolder) {
         int swipePos = viewHolder.getAdapterPosition();
         ItemGroup group = getGroup(swipePos);
 
@@ -584,6 +591,10 @@ public class NewTabPageAdapter extends Adapter<NewTabPageViewHolder>
         return mRecyclerView.findViewHolderForAdapterPosition(siblingPosDelta + swipePos);
     }
 
+    private boolean hasVisibleBelowTheFoldItems() {
+        return !mSections.isEmpty() || mSigninPromo.isShown();
+    }
+
     @VisibleForTesting
     ItemGroup getGroup(int itemPosition) {
         int itemsSkipped = 0;