📰 Tweak the suggestion ranks for UMA to handle fetchMore

chrome/android/java/src/org/chromium/chrome/browser/suggestions/SuggestionsMetricsReporter.java

+// Copyright 2017 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.suggestions;
+
+import org.chromium.chrome.browser.ntp.cards.ActionItem;
+import org.chromium.chrome.browser.ntp.snippets.CategoryInt;
+import org.chromium.chrome.browser.ntp.snippets.SnippetArticle;
+
+/**
+ * Exposes UMA related methods.
+ */
+public interface SuggestionsMetricsReporter {
+    /**
+     * Tracks per-page-load metrics for content suggestions.
+     * @param categories The categories of content suggestions.
+     * @param suggestionsPerCategory The number of content suggestions in each category.
+     */
+    void onPageShown(int[] categories, int[] suggestionsPerCategory);
+
+    /**
+     * Tracks impression metrics for a content suggestion.
+     * @param suggestion The content suggestion that was shown to the user.
+     */
+    void onSuggestionShown(SnippetArticle suggestion);
+
+    /**
+     * Tracks interaction metrics for a content suggestion.
+     * @param suggestion The content suggestion that the user opened.
+     * @param windowOpenDisposition How the suggestion was opened (current tab, new tab,
+     *                              new window etc).
+     */
+    void onSuggestionOpened(SnippetArticle suggestion, int windowOpenDisposition);
+
+    /**
+     * Tracks impression metrics for the long-press menu for a content suggestion.
+     * @param suggestion The content suggestion for which the long-press menu was opened.
+     */
+    void onSuggestionMenuOpened(SnippetArticle suggestion);
+
+    /**
+     * Tracks impression metrics for a category's action button ("More").
+     * @param category The action button that was shown.
+     */
+    void onMoreButtonShown(@CategoryInt ActionItem category);
+
+    /**
+     * Tracks click metrics for a category's action button ("More").
+     * @param category The action button that was clicked.
+     */
+    void onMoreButtonClicked(@CategoryInt ActionItem category);
+
+    /** Sets the ranker to use to compute some of the reported metrics. */
+    void setRanker(SuggestionsRanker suggestionsRanker);
+}