Implement a basic Site Engagement Score service.

chrome/browser/engagement/site_engagement_service_unittest.cc

+// 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.
+
+#include "base/command_line.h"
+#include "chrome/browser/engagement/site_engagement_helper.h"
+#include "chrome/browser/engagement/site_engagement_service.h"
+#include "chrome/browser/engagement/site_engagement_service_factory.h"
+#include "chrome/common/chrome_switches.h"
+#include "chrome/test/base/browser_with_test_window_test.h"
+
+using SiteEngagementServiceTest = BrowserWithTestWindowTest;
+
+// Tests that the Site Engagement score is initially 0, and increments by 1 on
+// each page request.
+TEST_F(SiteEngagementServiceTest, ScoreIncrementsOnPageRequest) {
+  base::CommandLine::ForCurrentProcess()->AppendSwitch(
+      switches::kEnableSiteEngagementService);
+
+  SiteEngagementService* service =
+      SiteEngagementServiceFactory::GetForProfile(profile());
+  DCHECK(service);
+
+  GURL url("http://www.google.com/");
+
+  AddTab(browser(), GURL("about:blank"));
+  EXPECT_EQ(0, service->GetScore(url));
+
+  for (int i = 0; i < 10; ++i) {
+    NavigateAndCommitActiveTab(url);
+    EXPECT_EQ(i + 1, service->GetScore(url));
+  }
+}