Add component for feature engagement tracking.

chrome/android/java/src/org/chromium/chrome/browser/feature_engagement_tracker/FeatureEngagementTrackerFactory.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.feature_engagement_tracker;
+
+import org.chromium.chrome.browser.profiles.Profile;
+import org.chromium.components.feature_engagement_tracker.FeatureEngagementTracker;
+
+/**
+ * This factory creates FeatureEngagementTracker for the given {@link Profile}.
+ */
+public final class FeatureEngagementTrackerFactory {
+    // Don't instantiate me.
+    private FeatureEngagementTrackerFactory() {}
+
+    /**
+     * A factory method to build a {@link FeatureEngagementTracker} object. Each Profile only ever
+     * has a single {@link FeatureEngagementTracker}, so the first this method is called (or from
+     * native), the {@link FeatureEngagementTracker} will be created, and later calls will return
+     * the already created instance.
+     * @return The {@link FeatureEngagementTracker} for the given profile object.
+     */
+    public static FeatureEngagementTracker getFeatureEngagementTrackerForProfile(Profile profile) {
+        return nativeGetFeatureEngagementTrackerForProfile(profile);
+    }
+
+    private static native FeatureEngagementTracker nativeGetFeatureEngagementTrackerForProfile(
+            Profile profile);
+}