📰 Use first seen position in suggestion UMA

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

 // Copyright 2016 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.cards;
 
 import org.chromium.base.Callback;
 import org.chromium.base.Log;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.chrome.browser.ntp.NewTabPage.DestructionObserver;
@@ skipping 17 matching lines @@
 /**
  * A group of suggestions, with a header, a status card, and a progress indicator. This is
  * responsible for tracking whether its suggestions have been saved offline.
  */
 public class SuggestionsSection extends InnerNode {
     private static final String TAG = "NtpCards";
 
     private final Delegate mDelegate;
     private final SuggestionsCategoryInfo mCategoryInfo;
     private final OfflinePageBridge mOfflinePageBridge;
-    private final SuggestionsRanker mSuggestionsRanker;
 
     // Children
     private final SectionHeader mHeader;
     private final SuggestionsList mSuggestionsList;
     private final StatusItem mStatus;
     private final ActionItem mMoreButton;
     private final ProgressItem mProgressIndicator;
 
     private boolean mIsNtpDestroyed;
 
@@ skipping 11 matching lines @@
     public interface Delegate {
         void dismissSection(SuggestionsSection section);
     }
 
     public SuggestionsSection(Delegate delegate, NewTabPageManager manager,
             SuggestionsRanker ranker, OfflinePageBridge offlinePageBridge,
             SuggestionsCategoryInfo info) {
         mDelegate = delegate;
         mCategoryInfo = info;
         mOfflinePageBridge = offlinePageBridge;
-        mSuggestionsRanker = ranker;
 
         mHeader = new SectionHeader(info.getTitle());
-        mSuggestionsList = new SuggestionsList(manager, info);
+        mSuggestionsList = new SuggestionsList(manager, ranker, info);
         mStatus = StatusItem.createNoSuggestionsItem(info);
         mMoreButton = new ActionItem(this, ranker);
         mProgressIndicator = new ProgressItem();
         addChildren(mHeader, mSuggestionsList, mStatus, mMoreButton, mProgressIndicator);
 
         setupOfflinePageBridgeObserver(manager);
         refreshChildrenVisibility();
     }
 
     private static class SuggestionsList extends ChildNode implements Iterable<SnippetArticle> {
         private final List<SnippetArticle> mSuggestions = new ArrayList<>();
         private final NewTabPageManager mNewTabPageManager;
+        private final SuggestionsRanker mSuggestionsRanker;
         private final SuggestionsCategoryInfo mCategoryInfo;
 
         public SuggestionsList(NewTabPageManager newTabPageManager,
-                SuggestionsCategoryInfo categoryInfo) {
+                SuggestionsRanker ranker, SuggestionsCategoryInfo categoryInfo) {
             mNewTabPageManager = newTabPageManager;
+            mSuggestionsRanker = ranker;
             mCategoryInfo = categoryInfo;
         }
 
         @Override
         public int getItemCount() {
             return mSuggestions.size();
         }
 
         @Override
         @ItemViewType
         public int getItemViewType(int position) {
             checkIndex(position);
             return ItemViewType.SNIPPET;
         }
 
         @Override
         public void onBindViewHolder(
                 NewTabPageViewHolder holder, int position, List<Object> payloads) {
             checkIndex(position);
             assert holder instanceof SnippetArticleViewHolder;
+            SnippetArticle suggestion = getSuggestionAt(position);
+            mSuggestionsRanker.rankSuggestion(suggestion);
             ((SnippetArticleViewHolder) holder)
-                    .onBindViewHolder(getSuggestionAt(position), mCategoryInfo, payloads);
+                    .onBindViewHolder(suggestion, mCategoryInfo, payloads);
         }
 
         @Override
         public SnippetArticle getSuggestionAt(int position) {
             return mSuggestions.get(position);
         }
 
         @Override
         public int getDismissSiblingPosDelta(int position) {
             checkIndex(position);
@@ skipping 223 matching lines @@
                 Log.d(TAG, "setSuggestions: removing all suggestions");
                 mSuggestionsList.clear();
             }
         }
 
         mProgressIndicator.setVisible(SnippetsBridge.isCategoryLoading(status));
 
         mSuggestionsList.addAll(suggestions);
 
         for (SnippetArticle article : suggestions) {
-            mSuggestionsRanker.rankSuggestion(article);
             if (!article.requiresExactOfflinePage()) {
                 updateSnippetOfflineAvailability(article);
             }
         }
 
         refreshChildrenVisibility();
     }
 
     private void updateSnippetOfflineAvailability(final SnippetArticle article) {
         // This method is not applicable to articles for which the exact offline id must specified.
@@ skipping 79 matching lines @@
     @VisibleForTesting
     ActionItem getActionItem() {
         return mMoreButton;
     }
 
     @VisibleForTesting
     StatusItem getStatusItem() {
         return mStatus;
     }
 }