Add a third point to snap the scroll to.

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

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.chrome.browser.ntp;
 
 import android.annotation.SuppressLint;
 import android.content.Context;
 import android.content.res.Resources;
 import android.graphics.Bitmap;
@@ skipping 431 matching lines @@
     private void initializeSearchBoxRecyclerViewScrollHandling() {
         final Runnable mSnapScrollRunnable = new Runnable() {
             @Override
             public void run() {
                 assert mPendingSnapScroll;
 
                 // These calculations only work if the first item is visible (since
                 // computeVerticalScrollOffset only takes into account visible items).
                 // Luckily, we only need to perform the calculations if the first item is visible.
                 if (!mRecyclerView.isFirstItemVisible()) return;
-                int currentScroll = mRecyclerView.computeVerticalScrollOffset();
+                final int currentScroll = mRecyclerView.computeVerticalScrollOffset();
 
-                // Scroll to hide all of content view off the top of the page.
-                // We subtract mContentView.getPaddingTop() to offset the contents below the
-                // search box.
-                int targetScroll = mContentView.getHeight() - mContentView.getPaddingTop();
+                // If snapping to Most Likely or to Articles, the omnibox will be at the top of the
+                // page, so offset the scroll so the scroll targets appear below it.
+                final int omniBoxHeight = mContentView.getPaddingTop();
+                final int topOfMostLikelyScroll = mMostVisitedLayout.getTop() - omniBoxHeight;
+                final int topOfSnippetsScroll = mContentView.getHeight() - omniBoxHeight;
 
-                if (currentScroll > 0 && currentScroll < targetScroll) {
-                    if (currentScroll < mSearchBoxView.getTop()) {
-                        // Scroll to the top.
-                        mRecyclerView.smoothScrollBy(0, -currentScroll);
-                    } else {
-                        // Scroll to the articles.
-                        mRecyclerView.smoothScrollBy(0, targetScroll - currentScroll);
-                    }
+                assert currentScroll >= 0;
+                // Do not do any scrolling if the user is currently viewing articles.
+                if (currentScroll > topOfSnippetsScroll) return;
+
+                // If Most Likely is fully visible when we are scrolled to the top, we have two

[mcwilliams, 2016/05/04 16:07:16]

If Most Likely is NOT :) visibile

[PEConn, 2016/05/04 16:12:02]

Nope, I think you misread the comment...

+                // snap points: the Top and Articles.
+                // If not, we have three snap points, the Top, Most Likely and Articles.
+                boolean snapToMostLikely =
+                        mRecyclerView.getHeight() < mMostVisitedLayout.getBottom();

[May, 2016/05/04 15:45:19]

Is it possible to have a case where the screen is small enough that there's no
MV at all at the start?

[PEConn, 2016/05/04 15:53:08]

The Most Visited is contained within the mContentView which is the first item in
the RecyclerView (which we check is visible on line 451), so mMostVisited will
exist.

+
+                int targetScroll;
+                if (currentScroll < mContentView.getHeight() / 3) {
+                    // In either case, if in the top 1/3 of the original NTP, snap to the top.
+                    targetScroll = 0;
+                } else if (snapToMostLikely && currentScroll < mContentView.getHeight() * 2 / 3) {
+                    // If in the middle 1/3 and we are snapping to Most Likely, snap to it.
+                    targetScroll = topOfMostLikelyScroll;
+                } else {
+                    // Otherwise, snap to the Articles.
+                    targetScroll = topOfSnippetsScroll;
                 }
 
+                mRecyclerView.smoothScrollBy(0, targetScroll - currentScroll);
                 mPendingSnapScroll = false;
             }
         };
 
         mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
             @Override
             public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
                 if (mPendingSnapScroll) {
                     mRecyclerView.removeCallbacks(mSnapScrollRunnable);
                     mRecyclerView.postDelayed(mSnapScrollRunnable, SNAP_SCROLL_DELAY_MS);
@@ skipping 582 matching lines @@
     }
 
     private int getVerticalScroll() {
         if (mUseCardsUi) {
             return mRecyclerView.computeVerticalScrollOffset();
         } else {
             return mScrollView.getScrollY();
         }
     }
 }